Hello I want to do a game with controls like drag and shoot.

But I did not find any video about it than this: https://www.youtube.com/watch?v=Tsha7rp58LI&t=3s

The video teaches you how to do it anytime but I want to let players drag and shoot the character(cube) only if the character is on the ground.

How can I do that with the code mentioned in the video?

Thank you for any answers.

First you should define a rule when you can be sure that your conditions are met, this can be if the character didn't move for a couple of frames or you detect a physics trigger. It is up to you to do further research, as I don't think someone will present full functional source code to you