Accessing/screen sharing a remote computer over the internet is not so easy. There are lots of ways of doing it but they all seem to need some setup...
Using Screen Sharing via Messages is the easiest, and free. However, I think it would require (on the MP in France) that a person be logged into an account that's signed into an Apple ID, which (I think) would have to be different from the Apple ID you (in CA) are logged in with on your MBP. Can that be arranged?
Note that the Remote Login setting in your post only applies to logins via 'ssh' on the local network -- by itself it won't work for login from any other network (like over the internet). Theoretically one could use port forwarding on the router, then (somehow) discover the remote network's IP address and then connect with ssh, but IMHO it's far too risky. (Any internet hacker could connect and try to guess or bruteforce your probably simple login password.)
You could run your own VPN server on one of your machines ( this is not a subscription to a VPN service) to make the two machines appear to be on the same local network, but that's only for the tech-savvy. I've read good things about Tailscale -- you might be able to use that, as I think it's free for non-commercial use and probably easier to set up.
After all, you're probably best off with a commercial product to solve the "remote access/screen sharing over internet" problem. I haven't used any of them, but TeamViewer and Jump Desktop are two examples that (I think) would work. There have been many threads about the merits of different solutions. I assume there are accounts to create and software to install.
I'm probably forgetting other possible solutions -- hopefully someone with chime in.