Integrate Microsoft Teams Audio calls in my application

Hello All

We have an android application, I want to Integrate Teams Audio calls in my application.

This is our user case: Customer use android application at reception desk, to call staff via MS Team service.

Function require detail:

- List all user of Microsoft Teams in the application

- Choose a user and make a call to user inside the application

Do the MS Team have any API help us do that? If yes, could give us document about it? If no, is there any special service MS Team for Microsoft Partner?

I look forward to your response.

Thank you so much.