I can't sign up for files.fm

for Google it says "Access blocked: this application sent an invalid request".
for Microsoft it says: "Failed to execute the request

invalid_request: The provided value for the input parameter 'redirect_uri' is not valid. The expected value is a URI which matches a redirect URI registered for this client application."
when registering by mail/password captcha does not work writes that: "ERROR:
invalid key domain"