Does it make sense for each subdomain to create an api subdomain for rest applications?

Question

API

I have a site domain.ru
Does it have a subdomain api.domain.ru Does
the site have a forum: forum.domain.ru
Do I need to create a separate subdomain api.forum.domain.ru for the forum?
There are also a bunch of other subdomains, for example, admin.domain.ru, sclad.domain.ru, shop.domain.ru, manager.domain.ru
Is it necessary to create an api subdomain for each subdomain in this case, using an example of how it is done with languages ​​and mobile versions of the site?
m.admin.domain.ru
m.forum.domain.ru
Thank you.

Answer 1

If these are completely different APIs that work with different data and are written by different people, then it makes sense to separate them. Otherwise - no.

Answer 2

And you can answer the question - "Why?" quickly and without hesitation? If so, then you need to create