how do I determine that an entity IS WALKING?

it is necessary to determine what kind of entity is WALKING, or tell me how to fix the cycling of the animation of walking (when the mob stopped walking and stood in place, it still walked in place), how to do this?

PLEASE DO NOT WRITE "determine the speed of the mob; Just set the inversion of the condition that the entity runs, etc. THIS IS ALL FROM THE CATEGORY OF "dude, just build a spaceship and open the universes, it's just""! or that there is already a similar post! none of this works and there is no such post!(there is, but the user is ignored there), or a specific example (the name of the function and where it is located, and in what connection with what to use or where to get the plugin) or ignore