on the pid, check this guide I made how to get the correct one: Instructions to install Py-spy on HAOS
top(to get pid for homeassistant)
and just to be sure the guide was still accurate I dd test the exact same commands, and no errors appeared.
are you sure you have the correct pid, and file installed?
(I take it the docker exec went ok given the command prompt, and the folders are there too, given no cd error was displayed)