No upload possible on shared link

Hi, I've created a shared link that I want to distribute to friends that don't have own pcloud accounts. I've activated the upload option for "everyone". But no upload option appears when I open the shared link.

When I set the upload option to "dedicated user with pcloud account" a button called "Hinzufügen" ("Add") appears.

Any suggestions what went wrong and how I can activate the upload option?