Nothing to do with any kind of Licences, you will need designer approval / permission to convert it,
and you will have only 2 choices:
1- buy his rights ( it will be higher than the extended license ).
2- team up with that designer and share the profit between you and him.
and about explanation of Extended license, as envato says ” Use, by you or one client, in a single end product which end users can be charged for ”, for example the revolution slider if you want to add it to your template you must buy Extended license if you will sell the final product here in TF.
1- Click on Edit tab from your template page
2- Add your Description. on Description text area.
3- Click on Save Changes not Submit Files for Review
Contact the support because your email in blacklist, it happened with me before.
Thanks @dtbaker it’s working fine now