That’s her prerogative! Not everyone likes oral sex. If you think she’s making it up because it hasn’t worked for her, then ask her about it. But she really just might not be into it.
Everyone’s got their own thing. Maybe she gets off on anal more than oral! Lol. Who knows? It’s not a bad thing that she just doesn’t like it, nothing to do with you.
The point is to find out all the other things she likes. There’s plenty! Trust me.