OK, I wouldn’t use a translator anyway, I prefer getting proofread by people. I didn’t try Grammarly and I admit that my main concern is idiomatic sentences and false friends with French, where I do a lot of mistakes in my drafts; but it seems that Grammarly also covers that, so it could help.
If you have specific bad sentences in mind, you can post them here. If you don’t remember, don’t worry, I still have that writing group on Nanoreno Discord that I forgot to contact after releasing the game.