I have just installed Nextcloud and do not want to have it able to be accessed from outside of my LAN. I want to use it ONLY to backup my local computers to using Acronis. I am not sure if i can use it as a FTP but for some reason I am not able to connect to it. Can someone please tell me how to make this work?
Ask your Acronis sales representative or Acronis support if they support Nextcloud as a backup destination. If they don’t support it, don’t even try it, because using unsupported storage targets in “hacky” ways will lead to disaster. And if things go wrong and you’re using the product in an unsupported way, you won’t get any support from Acronis.
Are you sure that FTP is supported by Acronis in the first place?
Anyway, one thing is for sure, Nextcloud can’t be accessed via FTP protocol, as @rakekniven already pointed out. So no, you can’t use FTP with Nextcloud.
If you want an FTP server, set up an FTP server, but do not use it with Acronis unless Acronis officially supports FTP, which again you have to ask Acronis support.