By "needs" I take it that you mean "is programmed in such a way to require" and not that the permissions are required to do the job you are asking of it?

ios allows the following permissions for your phone photo library:

- no access

- add photos only - can add photos to the library, but not access photos in the library

- limited access- the app can only access the photos you select

- full access - the app can access everything

Canon used to allow limited access. Now it refuses to work without full access to your photo library.

Honestly, it should allow any of those.