This can have various reasons that do not necessarily have anything to do with you. I can give you some possible explanations and tips on how to deal with it. 😊

She's just looking for sex. This is the simplest and most common explanation. She only writes to you about erotic stuff because she's only interested in a sexual relationship with you. She doesn't tell you much about herself because she doesn't want to make an emotional bond or commitment with you. In this case, you should accept their behavior and decide whether you want the same or not. If so, then enjoy the fun and be honest and respectful with her. If not, then tell her clearly and politely and look for another woman who shares your desires.
She is insecure or shy. Maybe she's interested in you, but she doesn't know how to have a normal conversation with you. She only writes to you about erotic stuff because she thinks it attracts or impresses you. She doesn't tell you much about herself because she's afraid of boring or scaring you off. In this case, you should be patient and understanding. Show her that you like her as a person and want to get to know her. Ask her questions about her life, her feelings, and her desires. Give her positive signals and encourage her to show more of herself.
She is busy or distracted. Maybe she has a lot of stress in her life, whether it's work, study, family, or other commitments. She may not have enough time or energy to focus on a relationship or check in regularly. She only writes to you about erotic stuff because she sees it as a kind of outlet or escape. She doesn't tell you much about herself because she doesn't want to or can't share her problems with you. In this case, you should be flexible and considerate. Show her that you give her space and support. Ask them about their plans and needs and adapt.
She plays with you or tests you. Maybe she's interested in you, but she wants to challenge or manipulate you. She only writes to you about erotic stuff to keep you happy or jealous. She doesn't tell you much about herself because she wants to make you curious or see your reaction. In this case, you should be confident and clear. Show her that you are not a toy and that you have serious intentions. Set limits and consequences for her and don't let herself be taken advantage of.