How many create FCM topics in a server

Question

My team was in trouble in push alarm with FCM token in flutter (especially ios),
So we decided to push alarm to each user with topics.

I know that "One app instance can be subscribed to no more than 2000 topics." in Firebase Document

But i confused about "One app instance". Is that mean each android or ios application user can subscribe 2000 topics? or Each FCM Server can create up to 2000 topics?

I wonder about One app instance's meaning in "One app instance can be subscribed to no more than 2000 topics"

Answer 1

It's 2000 per device, see this discussion

Answer 2

App instance refers to the unique installs. The 2000-topic-limit is applicable to per app install. More discussion here .