User rights

Hi,

We have the following project with power bi, to quickly explain:
-We, software developpers, create report templates with power bi desktop, and we publish them to be available to our customers
-Our customers send their data with the Power Bi Rest API, but their data is only available for their own users linked to each customer. Each customer has the same structure for the data.
-The customer must only see the data concerning him but can work or chose among the models we create.

What's the best way to do it?
Is it necessary to create one workspace per customer and publish each model in each workspace?
Or is it possible to create one workspace and allow each customer to work only with his own data?

Thanks for your help