How do i move in a direction instead of target position using PID Controller

all of the pid controllers i have found online takes a target position as the input, and then moves the object towards that position using forces at a certain speed. However i dont want my character to move towards a target position using forces, i want my character to move in a direction using forces while reaching a target velocity without clamping its velocity. How would i implement a pid controller to do this?

Just set the target position to your character’s position + the direction you want the character to move in.

i tried doing this before and it did not give me good results.