"Not yet ready to generate a collision!"
This message will appear if you run the "GenerateCollision" action before the parsing and merging process is complete.
Try using the "isReady" condition as shown in the image in the documentation.
Viewing post in "Add Tilemap Collisions" Extension for GDevelop comments
I went over everything and double checked - I think I got it! it still didn't work when I tried the "isReady" condition but I realized the map I tried to use had multiple layers and I think that might've been messing it up, but now it seems to work! Thank you so much for making this and for helping me so thoroughly