I would connect the pass to the next action.
A simple question is: “After you pass, where can you help next?” Sometimes the answer is run forward. Sometimes it is move sideways, support behind the ball or clear space for somebody else.
I would avoid a rule like “pass and move” if it turns into everybody sprinting after every pass.
Small give-and-go games can make the picture obvious, but then put it back into a normal directional game and see whether they recognise the moment themselves.
Praise movement that actually changes the defender or gives the player on the ball another option.
At U10 the message can stay simple: the pass does not finish your job. It often starts your next one.