License for plugins pro version

Hi, I have a question about the license, If an author wants to use the Elementor Pro feature like Single Post Template, for that product, must the author buy Elementor Pro License?

Elementor vs Pro is a bit different and if the template is supported by the free version, you ( author ) don’t have to purchase the copy.

I cannot understand. Elementor Pro cannot be included in the theme and I wanna use Pro features like Elementor Pro Theme builder.
What should I do? I can publish the theme but everyone who buys the theme should buy the Elementor Pro license as well. Does not it make any problem?

They offer “Expert” package for 1000 sites. You should be able to purchase and use it on your theme but read the terms and conditions before