Connecting a custom container azure function to a custom container azure web app.

Question

I have a containerized frontend deployed as an azure web app and a containerized api deployed as an azure function. Both are R-based, hence the decision on deploying them in such way.

I want to connect my frontend to my api, meaning making requests to that api from my frontend application. For that, I created a VPN and a subnet so they can be under the same network.

However, the frontend seems not to be able to reach the api. I have no errors from neither of the logs, so I really have no clue what could be wrong.

One thing I was wondering is if they are somehow not under the same bridge network, but I would expect they are, since in theory Docker creates a bridge virtual network by default, and connects the containers to it.