Almost finished  Gehe zur Training: GPG Challenge

I enabled GPG encryption. I read an encrypted email from WeChall robot. And what I should do next to complete this challenge?

There should be a link in that mail.
Many mail clients do not show the link correctly and you have to substitute & with & yourself, or switch to plain format in your account settings.

Yes, there was a link and I visited this page, but challenge is still unsolved.

It seems to me that all you have done so far is set up GPG. Now go finish the challenge.

I did all again and everything works fine, but what should I write as a password?

The password is sent in the mail when you hit the button below in challenge.

Unfortunately I did not receive a mail with password. What should I do then? Link is unactive after using. I can repeat everything once again, but it is now a bit annoying.

You say you did "all again and everything works fine", but that suggest you are only configuring GPG. Did you actually press the button 'Send me encrypted mail please.' on the challenge page? Did you get a message 'We have sent you an encrypted email to <your e-mail> which contains the solution.'? Did you check your spam folder?

Thanks for all, done.