My friend asked me to date, and I don't find them attractive

I (M19) have known a friend (19F) on discord for 2 years now and today she decided to share a photo of herself and left me a message saying that she wants to date me. The issue is, I don't know how to tell her I don't want to be in an online relationship without crushing her. I have nothing against online relationships at all and would be open to one, but it would just have to be the right person. Since she shared the photo ofc she will know that's the reason I don't want to do it, as she is not my type at all. From what she has said before is that she doesn't take care of herself, and I would rather date a girl that does and works out at the gym like me. How do I tell her I don't want to do it with her without making her feelings upset? And if the question about type/picture comes up, what should I say? Or should I just be straightforward with her?