How to open .pbix on app.powerbi.com

[purps]

Hello there, 

I am trying to open a .pbix within the  app.powerbi.com and not use Power BI desktop. However, I can't find anywhere to open a file and also the file that has been shared with me through teams won't show up in the 'Shared With Me' tab.

Are these strictly premium features that will be unlocked upon paying or am I missing something fundamental here? I'm especially confused as to why the 'Shared With Me' feature is not working.

Many thanks in advance.

D

[purps]

EDIT: I have powerBI Pro. Even more confused now...