Load error - relationships

I will have a go at these things but that data logic doesn't make much sense to me. Surely I would only use a many to many relationship if I needed to relate multiple session types to multiple session bookings? I just want to relate a single session type to multiple session bookings. This works well in my dataverse model-driven power app, so is it just Power Bi that works like this and requires the different relationship. I want to be able to keep my single form column lookup on my session bookings form in my app, so can I just create the many to many relationship in Power Bi and then will it work?

Thanks in advance