Just beat me to the punch, I was about to recommend this. KDE Connect is a wonderful piece of software that works on Windows, Linux and Mac (maybe idk). This only works if you have an android phone though, if it’s between iOS and a pc you’re SOL. The only thing I could really figure out was just uploading all the files from my phone or my PC I wanted to transfer onto gofile. Better than dealing with apple clouds and weird third party apps.