Abuse: Someone is impersonating my website trying to steal credetials.

Good morning! It appears there is a page hosted by this service that is a fake portal to my web application. They are emailing my clients asking them to verify their credentials, probably for the sake of stealing them. IS there a report or abuse department i can reach out to?
Hello,

you can either post the domain here or contact us at podpora@webzdarma.cz or abuse@webzdarma.cz