Photos on IOS Iphone do not duplicate

Hello,
I have a question about Nextcloud’s IOS client. This is what I want to do. I want to save the photos from my Iphone photo gallery in Nextcloud. But I want to delete them from my phone. Unfortunately I have them in the client of Nextcloud. So also on it again. So actually I want to make a photo on the Iphone. Then move it via Nextcloud Client to Nextcloud and delete the photo on the iphone. Then it should only be on the Nextcloud server? But how do I do that?

Translated with www.DeepL.com/Translator