You do not GET him to. You offer yourself and if he takes it then he takes it. Anything else is violating the number one most important thing- consent.
My males have always come to me even the first time/s. They are interested on their own without any prompting or bribery or anything else. I have permitted them to take that interest further, allowing them to sniff and lick and then mount up.
Oral on a dog is not as pleasant for them as for us. They may tolerate it after they have tied, but they may not. There are threads about it.