Link to InternetX

Please, I need your answer.
It’s for the Pro version.

Since you’re using the Pro version of this plugin we recommend you go to their official support channel so you can get support from the people who know it best.

https://codecanyon.net/item/wp-domain-checker/9959666/support

The vendors are the best resource for support of commercial products. Also, as the author is aware, commercial products are not supported in these forums.