WordPress: 403 error when trying to access a php page in my plugin's directory

Question

It works fine on my local server, but when I try to do it on the live server, it gives me 403 error.

Basically I have a plugin made, which has a settings page in the WordPress dashboard. In that settings page, there is a form with the action attribute leading to a different php page, that is located in my plugin's directory. On localhost, when I submit the form, the php page opens and the script executes. But when I try to submit the form on the live server, I get a 403 error when the form redirects to the php page.

I already checked file permissions using sftp and permissions are correct.

This is the.htaccess file of the live server:

# Begin GzipofBreezeWPCache
<IfModule mod_env.c>
SetEnv BREEZE_GZIP_ON 1
</IfModule>
<IfModule mod_deflate.c>
AddType x-font/woff .woff
AddOutputFilterByType DEFLATE text/plain
AddOutputFilterByType DEFLATE image/svg+xml
AddOutputFilterByType DEFLATE text/html
AddOutputFilterByType DEFLATE text/xml
AddOutputFilterByType DEFLATE text/css
AddOutputFilterByType DEFLATE text/vtt
AddOutputFilterByType DEFLATE text/x-component
AddOutputFilterByType DEFLATE text/javascript
AddOutputFilterByType DEFLATE application/js
AddOutputFilterByType DEFLATE application/x-httpd-php
AddOutputFilterByType DEFLATE application/x-httpd-fastphp
AddOutputFilterByType DEFLATE application/atom+xml
AddOutputFilterByType DEFLATE application/json
AddOutputFilterByType DEFLATE application/ld+json
AddOutputFilterByType DEFLATE application/x-web-app-manifest+json
AddOutputFilterByType DEFLATE application/xml
AddOutputFilterByType DEFLATE application/xhtml+xml
AddOutputFilterByType DEFLATE application/rss+xml
AddOutputFilterByType DEFLATE application/javascript
AddOutputFilterByType DEFLATE application/x-javascript
AddOutputFilterByType DEFLATE application/x-font-ttf
AddOutputFilterByType DEFLATE application/vnd.ms-fontobject
AddOutputFilterByType DEFLATE font/opentype
AddOutputFilterByType DEFLATE font/ttf
AddOutputFilterByType DEFLATE font/eot font/otf
AddOutputFilterByType DEFLATE font/otf
AddOutputFilterByType DEFLATE font/woff
AddOutputFilterByType DEFLATE application/x-font-woff
AddOutputFilterByType DEFLATE application/font-woff2
AddOutputFilterByType DEFLATE image/x-icon
</IfModule>
# End GzipofBreezeWPCache
#Expires headers configuration added by BREEZE WP CACHE plugin
<IfModule mod_env.c>
 SetEnv BREEZE_BROWSER_CACHE_ON 1
</IfModule>
<IfModule mod_expires.c>
ExpiresActive On
ExpiresDefault "access plus 1 month"
# Assets
ExpiresByType text/css "access plus 1 month"
ExpiresByType application/javascript "access plus 1 month"
ExpiresByType application/x-javascript "access plus 1 month"
ExpiresByType text/javascript "access plus 1 month"
# Media assets 
ExpiresByType audio/ogg "access plus 1 year"
ExpiresByType image/bmp "access plus 1 year"
ExpiresByType image/gif "access plus 1 year"
ExpiresByType image/jpeg "access plus 1 year"
ExpiresByType image/png "access plus 1 year"
ExpiresByType image/svg+xml "access plus 1 year"
ExpiresByType image/webp "access plus 1 year"
ExpiresByType video/mp4 "access plus 1 year"
ExpiresByType video/ogg "access plus 1 year"
ExpiresByType video/webm "access plus 1 year"
# Font assets 
ExpiresByType application/vnd.ms-fontobject "access plus 1 year"
ExpiresByType font/eot "access plus 1 year"
ExpiresByType font/opentype "access plus 1 year"
ExpiresByType application/x-font-ttf "access plus 1 year"
ExpiresByType application/font-woff "access plus 1 year"
ExpiresByType application/x-font-woff "access plus 1 year"
ExpiresByType font/woff "access plus 1 year"
ExpiresByType application/font-woff2 "access plus 1 year"
# Data interchange
ExpiresByType application/xml "access plus 0 seconds"
ExpiresByType application/json "access plus 0 seconds"
ExpiresByType application/ld+json "access plus 0 seconds"
ExpiresByType application/schema+json "access plus 0 seconds"
ExpiresByType application/vnd.geo+json "access plus 0 seconds"
ExpiresByType text/xml "access plus 0 seconds"
ExpiresByType application/rss+xml "access plus 1 hour"
ExpiresByType application/rdf+xml "access plus 1 hour"
ExpiresByType application/atom+xml "access plus 1 hour"
# Manifest files
ExpiresByType application/manifest+json "access plus 1 week"
ExpiresByType application/x-web-app-manifest+json "access plus 0 seconds"
ExpiresByType text/cache-manifest  "access plus 0 seconds"
# Favicon
ExpiresByType image/vnd.microsoft.icon "access plus 1 week"
ExpiresByType image/x-icon "access plus 1 week"
# HTML no caching
ExpiresByType text/html "access plus 0 seconds"
# Other
ExpiresByType application/xhtml-xml "access plus 1 month"
ExpiresByType application/pdf "access plus 1 month"
ExpiresByType application/x-shockwave-flash "access plus 1 month"
ExpiresByType text/x-cross-domain-policy "access plus 1 week"
 </IfModule>
#End of expires headers configuration
# BEGIN WordPress
# The directives (lines) between "BEGIN WordPress" and "END WordPress" are
# dynamically generated, and should only be modified via WordPress filters.
# Any changes to the directives between these markers will be overwritten.
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

Answer 1

The 403 Forbidden error appears when your server denies you permission to access a page on your site. This is mainly caused by a faulty security plugin, a corrupt .htaccess file, or incorrect file permissions on your server.

Change your file permissions. Deactivate your plugins. Delete and restore the .htaccess file. Deactivate your CDN. Check your hotlink protection.

Answer 2

Solved

This issue occurred due to server host configuration (Cloudways). There was an option that by default prevented php scripts from being run. After enabling this option the issue was resolved.