Thanks, I managed to solve the problem with your help.
But I started using cloudflare and WP Rocket on my site and are occurring two problems with the plugin:
First. Error in email layout. See here: https://imgur.com/a/QFbzY
Second. Doesn’t appear the message “registration confirmation”, when the user enters the e-mail in a product without stock. See here: https://acaradiscus.com.br/loja/camisetas-acaradiscus/camisa-keep-calm/
Thanks for the help.