Here’s an article from Scriptmag about writing with subtext in mind. For example to get across a character’s emotional state, instead of saying “He is stunned,” try “The air rushes out of his lungs.” Describe specific actions, then let the reader (and actor) interpret the state of mind.

More examples at https://scriptmag.com/screenplays/shh-subtext-the-powerful-sound-of-show-not-tell

(Scroll past the first part about teaching to get to the parts about subtext.)