Problem with Cyberpanel Firewall! Can't activate a key for a wordpress plugin

Unfortunately I own a problem and I do not know what to do. Running wordpress on a Vultr Cyberpanel host. Now I wanted to enter a key for the plugin Duplicator. But unfortunately it does not establish a connection and I suspect that it has something to do with the Cyberpanel firewall.

Unable to communicate with Please see this FAQ entry for possible causes and solutions.

Does anyone have a solution for me how to activate my key?