I'm not sure what approach should I take. How should I get her back one day, full no contact? Low contact? Tomorrow it's her birthday and I will wish her happy birthday that's so baseline for me I can't just ignore her like she does.
"no contact" is a tool to use when you are trying to detach from a breakup. if you want her back, think of contact more in terms of reading the room; if she has you blocked, its probably not a good idea to try to get around that.
in order to reconcile the relationship, you have to be able to step back from the conflict and your feelings, and look at the bigger picture: what is the conflict between you? how badly has the relationship broken down and why? what is it going to take, if possible, to get it on the right track?
the first and most important step is to stop the bleeding...dont let the conflict get worse. you can learn to do this here:
https://bpdfamily.com/message_board/index.php?topic=111890.0