Aggregators and SIOB aggregators host ip value

I am having a problem when configuring local development environment using SIAB image.

Our application logic (written by another developer) is written such that it queries the aggregators table (for host and port) and based on what aggregators are online it connects to them and then calls SQL that creates a new user. It creates problem when using SIAB because in the aggregators table the host there is 127.0.0.1 and so the application will fail trying to connect to it (because it needs the IP of the SIAB container or its name instead). I am trying to figure out how to fix this, but since I dont understand why is he connecting to all of the aggregators for this purpose (of creating users) instead of just connecting to the database as usual.

If its not necessary to call the SQL on all of the aggregators, I could rewrite the app logic to only call it on the “main” database host IP, if not (and he is connecting to the aggregators for some reason) can this host IP be reconfigured (in SIAB) to show the IP of the db container from the point of view and the docker-compose network?