Get a 4 post 12volt 30 amp automotive relay with base, this is the most common automotive relay and is cheap $4-$6.
Get a 15amp inline fuse and holder.
Mount relay in engine bay
relay connections will have odd numbering
85
86
87
30
30 is for Load power, the "load" is your fog lights, the power is from the 15amp fuse
So fuse hooks to battery power and 30 on the relay.
87 hooks to the fog lights, this connection only has power when relay is ON
85 and 86 are the low amp relay activation connections, there is no positive or negative polarity with these, if one has 12volts and the other has Ground then relay will be ON, if you remove the 12volts OR the Ground relay will be OFF, this is important.
Now you have two options
Run relay activation with Key ON power or 24/7 power(so lights can be on without key on), up to you really
Hook 85 up to 30 if you want 24/7 power, or hook it up to Key on power in engine bay, Coil's "+" wire can be used.
ON/OFF, from 86 run 1 wire into the cab to a switch, switch will also have a short wire to a cab's Ground.
So when you turn the switch on, the relay is Grounded and turns ON, passing power from battery to fog lights
Using the Ground as the on/off is better than running a 12volt wire, less chance of a short and melted wires
The Fog Lights also need to be Grounded, but I am sure you knew that part