Hi @Ilona ,
According to my research and testing, Sites.FullControl.All
permissions is required if you want to get the site permission. Hope it can help you .Thanks for your understanding and support.
More information for reference:
https://learn.microsoft.com/en-us/graph/api/site-get-permission?view=graph-rest-1.0&tabs=http
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.