I wanted to post a thing I made with panther on the scratch website, but i don't know ho to change the .pt to the .sb one, Itried with changing putting the format at the end of the name, but it didn't work, any help?
Of course it wouldn't work. There are incompatible blocks in Panther. And they are both in 2 different formats.
You aren't allowed to upload mod files onto the Scratch server, either. Upload it onto the mod's dedicated webpage for uploads (if it exists) instead, or use ModShare.