If COURSE is coaded as FRXUVH, how is RACE coaded in that code ?

I didnt find this answer i got it off quora from peter anderson just fyi

Explanation:

Here’s a step-by-step:

Convert the letters to numbers like so:

C = 3 , O = 15, U = 21, R = 18, S = 19, E = 5

F = 6, R = 18, X = 24, U = 21, V = 22, H = 8

Subtract them:

( 3 3 3 3 3)

As you can see, every letter is coded +3 letters, so ‘RACE’ would be:

R = 18 + 3 = 21 = U

A = 1 + 3 = 4 =D

C = 3 + 3 = 6 = F

E = 5 + 3 = 8 = H

can you show the map