Approch her in a friendly way and show interest in her as a person.Avoid making assumptions about her beliefs and respect her opinion
2. Spend time together
Try to spend time with her in a non- romantic way like hanging out as friends or doing activities together this will help her see you as more than just a potential partner.
3.Be patient and understanding
Understand that she may have her own reasons for not beliving in girlfriend or boyfriend thing and try to be patient with her. Don't rush things and let the relationship develop naturally
4. Communicate your feelings
If at some point you feel comfortable , you can exoress your feeling for her in a honest way. Be clear that you respect her decision and are willing to just be friends if she desires but also let her know how you feel about her.
5. Respect her boundaries
It's important to respect her boundaries and not pressure her into anything she is uncomfortable with. If she says she is not interested in a relationship, accept that and don't try to change her mind.
6. Stay genuine
Be yourself and don't try to be someone you're not .If she can see the real you and appreciates your company , she might eventually become interested in a romantic relationship.