A channel generally doesn't appear in the channel store if it unsupported by your user account location and the location the Roku is in. So if your Roku account was created via a UK computer, and you're using your Roku connected to a UK Internet connection, I would expect it to work. If you have a VPN involved anywhere in the chain, all bets are off.
Your best bet would be to contact the France TV provider and ask them the question directly. They have the only control over where a channel is made available and where it will work. Roku themselves does not control that.
Roku does have employee moderators on this forum, but I have my doubts that they could provide an accurate answer to that question. They would likely point you to the provider, although they might have a link to offer.
Dan
Roku Stick (3600), Ultra (4640), Ultra (4670), Ultra (4800), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.
