How to run a report using service/proxy account?

using powerbi semantic models, how do i design a report to access it with a proxy account not pass through?

give you an example, I have a semantic model with rls setup and need to build two reports, one report will pass through user credentials and using rls. and another one will use proxy account to give the same access to any viewer. some of the users might not even have shared access to the semantic model. Once we have rls added in the model, I think we have to use them in order to run the report.

but if they do, they might be secured by rls instead of wide open in case the model will be shared. How can we keep them have the same access in the second report which means using proxy account

This can be easily implemented in powerbi/ssrs onpremise, but powerbi service only provide pass through option. If we do not have any role created, this is fine. but once we use roles, this becomes issues.