Currently, there's no way to add photos that are already stored in Proton Drive to Photos when using the web interface. The only options are:

• Use the iOS or Android app
• Upload directly from your computer to Photos

Requested feature: Add the ability to browse Proton Drive and select existing photos/videos to add to an album, directly from the web interface.

Bonus: Ideally, this should work by reference rather than creating a duplicate. Adding a photo from Drive to an album shouldn't consume twice the storage quota.

Use case:Users who have already uploaded and organized photos in Proton Drive shouldn't need to switch to a mobile device or re-upload files just to add them to an album. This is especially relevant for users who primarily use the web interface or are working with large batches of photos already in Drive.