You should indicate what the problem is here for troubleshooting, otherwise technical support cannot help you. If you want to indicate Ukrainian information, then I would use Ukrainian as your topic. There is a report feature on each page. It is best to send specific notes at the specific site. If it is something over all, perhaps at the incubator page, you could click on a contributor to send a note to that person: https://www.duolingo.com/SergioRuido

Probably the Ukrainian sub-forum?