Hi
If you really wanted to you could try some super glue gel and attempt to reattach the silicon but but silicon in picky to adhere to things so you might as well replace them as apple sells them quite cheaply
Here’s a link to them
Small
[link|https://www.apple.com/uk/shop/product/MY3U2ZM/A/airpods-pro-1st-generation-ear-tips-2-sets-small|https://www.apple.com/uk/shop/product/MY3U2ZM/A/airpods-pro-1st-generation-ear-tips-2-sets-small|new_window=true]
Medium
[link|https://www.apple.com/uk/shop/product/MY3V2ZM/A/airpods-pro-ear-tips-2-sets-medium|https://www.apple.com/uk/shop/product/MY3V2ZM/A/airpods-pro-ear-tips-2-sets-medium|new_window=true]
Large
[link|https://www.apple.com/uk/shop/product/MY3W2ZM/A/airpods-pro-1st-generation-ear-tips-2-sets-large|https://www.apple.com/uk/shop/product/MY3W2ZM/A/airpods-pro-1st-generation-ear-tips-2-sets-large|new_window=true]
Or you could use the left over ones from inside the box
Hopefully this helps
Any questions please ask
Thanks:-)