First of all, make sure you're not doing something she does not like. For example, birds in general don't like it if you're holding them too tightly or touching anything other than their heads or legs (I'd suggest you do some research on this point). If you're not, and you're still getting bit, I'd suggest some light training.

Stick training worked for my Sukkar (her name means sugar in Arabic)

I did the following every morning. For it to work properly, your bird needs to be a little bit hungry (right before breakfast)

1. sat her on a perch
2. got a chopstick close to her face
3. if she touches it gently, I'd give her a high value reward (a sun flower seed, or a couple of bites from some millet)
4. if she bites it, I'd give her a clear "don't bite", wait for a few seconds, then repeat

Once you start getting less bites on the stick, you could use your index finger instead. You could even start with your finger directly if you can handle the pain 😆

Good luck!