Lost macbook remote locking not working

He there, 

I lost my macbook. I did have „Find my“ activated. Now I am trying to lock it remotelly. I tryed it via my iphone as well as icloud in a browser. It says it’s waiting and I don’t see a way how to finish it. I do use the e-mail connected to my Apple ID.

I go through all the locking steps. I fill in the message the macbook should show once somebody connects it online etc but I don’t receive any verification mail from Apple and I don’t have a chance to set up the new locking password. 

Anybody any suggestions? Thank you