Django routers and migrations?

Question

Django

There are two databases, for example A and B, A is default There is an app
, let's call C, with models and migration files, these data should be stored in B
Run migrate with your hands, specify the key to use B, the models arrived there and the django.migration table was created
There is a router , which says that if app == C, return db ==
B and for everything else the logic was used by default, or from the following routers?
And it turns out that it creates all the tables in the default database and enters information about migrations into the same default table