There’s ways to explore sexuality besides sending nudes to strangers and being tricked into transactional relationships that exploit their sexuality.
Everyone matures at different rates, but I think it’s pretty universal that no 13 year old is mature enough to consent to nude photos sent to strangers who are likely adults. Not to mention it’s criminal.
Would you prefer them to just not explore their sexuality?
Or explore it online with people they know, like their classmates?