CF7 is not Validated

I would like to validate CF7 on a local network, but I have the error shown in the attached image. How can I fix it?
Thanks in advance.

your local server is not online or can not connect to our servers!

I think it is the second reason. The corporate network is able to access the internet. Joomla can receive updates and install extensions. Does this mean that if I purchase the license I will not be able to use it anyway? How can I fix it?

then most propably your curl on the server is not enabled OR there is a specific list of allowed domains and our server should be added to the list!