Test with and Without Authentication issue

Hi everyone, 

I've been trying for the past three days to follow the instructions in the Deploy Agent Authentication trail, but I had to restart the modules.

When I started the module mentioned in the title, Agentforce agent responded with the following message:

After entering my email, I received the following message:

My question is ¿Why doesn't appear the validation code prompt after I entering the email?  

Do you have any solutions or recommendations, please?  

Best regards.