@Sandy154
I don't know if the email can be resent, but I used my travel coupon last month. I was booking a room and when it came to paying, there was the option saying 'use voucher' or something similar, and the voucher number appeared on the screen, and you just click it to use it!
Be careful though, if you need to cancel the booking, hosts on this forum say that you seem to lose the voucher money. Similarly, if you don't use all the voucher in one booking, they say you seem to lose the balance.