Side-Mirror Turn Signal

[Fast69Mopar]

The driver side will flash when unlocking the truck but not when signal is engaged. Do I need to replace the light fixture?

If the lamp flashes when you unlock the truck with the key fob then the lamp is still good and the issue is elsewhere.

If the lamp is not flashing with the turn signal then it is not receiving the input from the turn signals and the BCM depending on what year the truck is.