How can I undo an accidentally changed a keyboard setting that affects Photopea's pen tool?

I accidentally pressed something in Linux Mint Cinnamon 22.2, and an indicator that something had changed appeared. Now, when I use Photopea , I see a difference in the pen tool. The pen tool usually allowed you to click a point with the Alt key to cancel the next path's curvature, but now it seems I've to press Alt Gr (the right Alt in my layout) to do that. How can I undo that?

Question by Matheus Ryujinx on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.