why isn’t my self tanner working?

so i self tanned hourssss ago and it worked on my hands, (kinda) my arms, face but my stomach, back and legs are still pale!

i shaved and exfoliated the other day, i showered and moisturized before self tanning and let my skin breathe and dry a bit before tanning

not sure why it didn’t stick to my legs, stomach, or back

help? advice?