Nextcloud integration for file uploads within wordpress form or Rainloop

It would be kind if someone could give advice in advance so that I go in the right direction.

I’m a musician and want to set up a WordPress website for online mixing & mastering music.

So, I have to give my clients the possibility to upload their files (wav-files, etc.) within a form.

Maybe 200mb per file and limit to 5GB for the whole upload.

Is it possible to integrate nextcloud for this task in WP-Form or Rainloop?

And how exactly would this work?

same here. I also want to offer a free service on my website and give the visitors the ability to upload files on my WordPress site to Nextcloud.