I can diagnose your plant with a cute case of little guy infestation

Google Lens suggests a Tent Catapiller.

I remember our yard absolutely teeming with tent caterpillars as a little kid. Cute little guys–I remember I’d pet them because they were soft and fuzzy. I did freak out when I discovered their defense mechanism: vomiting up their stomach contents, which manifested as a green or red bubble the size of their heads. I thought I’d accidentally squished them at first and was really upset!

Kill them with fire.

Tent caterpillars larva will kill your tree and then come back the next season to kill the trees around them.