Record of the day a user is registered in looker studio

Hello, for the digital kit in Spain I am asked for proof where the date from which users have permission to use the looker studio is stated. How can I obtain this? Or something that justifies that since day x/x/20xx a person has access to the looker?

I know you can access the Looker Studio log events to see when users took actions in Looker Studio. Maybe this is a good starting point?