Trying to implement death in the game but when on the 3rd death the game crashes and sends an error

[austere peak]

I think it's just possible that old player object intersects with new scene ender. The problem is that after one second, the call to get_tree may fail if you're running a second time because of that.
You could probably weasel around it by saving the get_tree in a variable.
You could check if this is running an unusual number of times by adding a print statement.
You could prevent it running an unusual number of times by giving it a (static!) counter of times run and only letting this instance run one at a time

[outer oracle]

saving it in a variable worked! thank you very much, but what is the logic in this?

[austere peak]

It isn't in the tree during the second run.