Podio API Key Generator is returning "is not a valid domain" error

Question

I'm trying to generate a API key using https://podio.com/settings/api menu. Whatever I put in "Full domain (without protocol) of your return URL (e.g. mypodioapp.com)" field is returning "is not a valid domain". I don't understand what is asking me for. Is this my domain ? Or something else? Any help will be appreciate it.

Answer 1

For anyone who has same issue if you type simply localhost it is going to work.