Looking for Gui library C++

I'm not 100% sure if this is what you're looking for but the two main guis I know of and have messed with would be ImGui and zgui. They're both open source and can be found on GitHub. Although, ImGui does have a lot bigger community if you were ever to need some help with implementing or modifying it. Zgui on the other hand is fairly simple and clean but there are very few that actually use it and would know the ins and outs of it.