Openjournalsystems.com - access limited (wordfence)

After attemting to visit the page openjournalsystems.com/ojs-customization I become a message from Wordfence (??):
“Your access to this service has been temporarily limited. Please try again in a few minutes. (HTTP response code 503)”.
What does it mean?

Hi @Spaik,

openjournalsystems.com is not related with the PKP, so posting questions here will not help.

Regards, Primož

Thank you! Understand )