Being mechanically inclined, dig in. Not sure why your mechanic was changing fuses or which fuses he changed.
First, as someone mentioned, and this assumes you are referring to the fog lights, are they actually “on” at the switch?
Second if on, but not illuminated, open the frunk lid, then remove the two small black access covers. Ensure all the connectors are joined and seated. If someone previously removed the frunk, always possible the lights were not reconnected.
As a last resort before using your meter, remove the right side only fog light bulb access cover. Disconnect the bulb electrical connector and temporarily connect a known good bulb.
The question though, have the lights ever worked?
Are you checking them with the Spyder running or simply key on. With key on and not running I believe the lights will not power on.