Looks like ford does sell just the turn signal lamp around $200 according to my estimate software but no vin was provided so that could change when you call your local ford dealer.

You will have to remove the mirror assembly, then carefully remove the glass without breaking it or the clips, then take the back cover off the assembly, then get to the bolts for the light. Then reassemble and put back together and hope you don’t have to send it to the dealer or shop to have the 360 camera recalibrated for the towing features and lane guidance features. I guess this could all be done with the mirror still on the truck but it’s awkward that way in my opinion.