The ICO has fined an organisation almost £250,000 for failing to put in place basic protections to prevent children from accessing harmful and inappropriate material.
You can read the ICO ruling at https://ico.org.uk/about-the-ico/media-centre/news-and-blogs/2026/02/imgur-owner-medialab-fined-over-children-s-privacy-failures/, but you can learn from this too.
If you are processing material that is inappropriate for children to access, you should consider implementing age checks. There is a lot to consider here and a good starting point may the ICO’s Children’s Code https://ico.org.uk/about-the-ico/what-we-do/information-commissioners-opinions/age-assurance-for-the-children-s-code/.