NPC that cannot see player but can detect movement

I want to create an AI that will only chase the player if they make a movement but will stop its pursuit when the player stops movement
I am relatively new to scripting, I think it may have something to do with vector3 or Cframe but I dont know too much about them

I tried looking on youtube and looked through many google searches but to no avail.

Im assuming your having an issue with the targetting rather than moving the npc itself,
for this you would want to track the velocity of the HumanoidRootPart of nearby characters, if the velocity isnt 0 then the player is moving

Apparently Velocity Isn’t used anymore, I would have a script store a players old position and compare it to the players current position and check if the distance is more than 0, then just store all that data. (May not be the best fix)