Yes indeed Pigeons and Doves can and do sometimes mate when they don't have any other option.
Some people will put doves and pigeons into the same cage or coop and then eventually they will usually decide to mate up with each other.
However out in the wild a pigeon and dove rarely mates but sometimes if they don't have any other mates they can and do sometimes mate.
I've witnessed a dove and pigeon mating together one time in a park and it's first I've seen it so it can happen.