@Anonymous
As @RobElliott said, most of the premium connectors require a license with a particular vendor. Others such as the HTTP connector do not require a vendor license.
In addition, if I read the licensing guide correctly, the license for Power Automate that is included with the Office 365 license does not allow for using Premium connectors of any type. You need an upgraded license to use any premium connector.
Note: licensing is a "dark art" and I defer to the Microsoft licensing people on this....
Here is a link to the licensing page
The following is from page 14 of the licensing guide:
