Would love your opinions on how to play a situation that I have come across several times lately and I am probably handling it wrong.

1. Assume 6max NL table with unknowns and 100BB stacks. Its folded to you.
   Suppose you have pocket 8s in the Hijack and raise it up 3BB. If the BTN 3bets you 9BB, what do you do?

1.1 Now suppose it was the SB who 3Bet. what then?

1.2 How does this situation change if you have 55 or lower?

Surely there is a GTO solution in here somewhere. All comments appreciated. I get that sometimes it will be player dependent, but I'm hoping to at least have a default strategy for facing this situation against an unknown. Thanks again for any help.