Found the cause! I was playing on a 21:9 ultrawide monitor, and it seems the UI was getting cut off or misplaced due to the aspect ratio. When I changed my display settings to 16:9, the 'Finish' button finally appeared!!
I watched a video of someone else playing, but the "Finish" button doesn't appear in my game!! I tried re-downloading the game and playing it on the web, but the same issue persists.
