I’m not an iphoner, but I think you will, one way or the other, need some sort of intermediary. I personally host nextcloud, so that would work. I’ve heard good things about syncthing, but haven’t tried it myself. Signal allows sending yourself messages and has a desktop client that you could use.
There’re probably a ton of options.
Sysadmin/syseng/devopsy with the hobby in computers. Yea, I’m fun at parties.