Hi dear Make Community!!
I built a tutorial that explains how to build a new Custom App, step-by-step.
The lucky ones that already have a subscription to the french provider Free Mobile, and those that want to get started with Make Custom App can have a look here: https://jet-sceptre-57f.notion.site/How-to-build-a-Custom-App-connector-in-Make-for-the-Free-Mobile-API-90163363c746497887ace8d3d6176bc1
Let me know if you have any questions