Child theme

Hello.
I would like to add a child theme to DirectoryPress 9. I uploaded the theme Find Me from April 3, 2019.
It does not appear in the themes. If I go to Add a child theme, I see the message:
An unexpected error occurred. There could be a problem with WordPress.org or the configuration of this server. If you continue to experience this problem, please visit the support forums.
What to do ?