It's easy to find the apparent answer in basically all PUA books, or even posts from this forum from like 2007-2015 or so. (Most people won't give you them answers on here nowadays, and rightly so!)
The answers you will get from reading the books and looking at old posts etc, is that you need to create attraction in her. That will of course make her want to flirt with you. (girls don't tend to flirt with a guy who approaches them who they are not attracted too lol)
How to creat attraction? Depends on which guru you listen too.
So it could be 'negs' and DHV stories if 'mystery' is your guru
It could be 'cold reads' and assumptions/teasing if you follow the London Day Gamers
It could be being extremely 'direct' in your intentions if you like the Mode1 style PUA's
It could be by being self amused and free from outcome etc if you believe the RSD guys
It would be NLP sentences (embedded commands etc) if you like Ross Jefferies
I could go on
However, as
@CornbreadFed says, it's just fantasy.
You can't negotiate attraction. Having 'game' means closing a higher percentage of the girls who are attracted to you, than the dude who always drops the ball when girls are attracted to him. You can't 'make' them attracted. You could come across as the most confident, masculine guy she's met in ages who is funny and charming and interesting etc etc, but if you're not her type, it's dead in the water. Infield footage ironically proves this (look carefully at how each interaction starts/her reaction/and how the infield ends. You can tell within seconds whether he has a shot or not. His game and techniques are irrelenvant to her if you're not her type)