How can I connect a SQL database to a webhosted site with IIS on the web?

Question

I am building a test web application in asp.net core and I have hosted my site from laptop. Everything seems good but when I go to access any database related page the page just loads for a bit until it gives me an error and prompts me to go developer mode to see more relevant information(which I can't because the site is not on localhost it is on the web). I tried to change my connection string to different iterations it did not work, the site works locally with IIS express. Frankly I do not know what to do the documentation seems to be not existent so I would appreciate your help. You can test the website at http://digital60.ddnsking.com/ .

The connection string in use is:

"ConnectionStrings" : {
   "Default": "Data Source=DESKTOP-BULSITK\\SQLEXPRESS;Initial Catalog=TimsDinerDB;Integrated 
    Security=True;Connect 
Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False"
}

The database related pages are Create Order, List Foods, List Orders

This setup as mentioned previously works locally but when I host my site on the web it just does not connect, the hosting occurs from laptop in both cases(no change of OS or hardware on anything). I cannot post all the code of the test site here but if it is necessary I could put all the code in github, but I do not thing this is the problem.

Answer 1

Ok so after a lot of hours I fixed it, I am not exactly certain what fixed it but I believe it was probably my changes on the connection string, So the final connection string was:

"ConnectionStrings": {
"Default": "Server=.\\SQLExpress;Initial Catalog=TimsDinerDB;User Id=sa;Password=[Password];Connect Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False"}
}

you have to first activate the sa(server administrator) user from sql server for this one to work, and fill the password with the password you add to the sa user. I will try to see if it can be done with other users too. Other change I made was in security to add the IUSRS permissions to read write and modify but I am not certain if that was necessary.