app and login

Hi all,
I have to develop an app for some users, about 20.
This App must have access via login and password
and the data must be on SQL SERVER.
I would like to do all on Azure, but reading around I find many solutions and I don't understand which one is the best.
First figure out whether to use my Azure account or create a new one for the customer. And then, how to proceed to make the right choice.

The only thing I figured out is to build the app on VS2019 and publish it on Azure.

Thanks for suggestions
Greetings