Let users create category?

I’m using this in tandem with a mapping plugin to let cyberbullying victims and survivors of sexual harassment submit their stories anonymously to a digital rights organization. The people will select the appropriate location category from the dropdown; since I can’t possibly pre-create every single location they may report from, is there a way to let users create a category on the fly, or at least suggest it?

https://ww.wp.xz.cn/plugins/user-submitted-posts/