Our view of intimacy is shaped by preconceptions, some we learned from experience, or read about, or saw on screen.
A commonly held belief is the dominant partner should take the initative and make scenes happen, whilst submissive partners do what they're told. This is fine when the spanker loves spanking, but presents a problem if the recipient is keener on being spanked than their partner is on delivering it.
The principle that the top is the one in charge simply because they're the onr in the dominant role is too simplistic for the reality of partners with different sexual tastes.
A far better rule is the one who is keenest on a particular activity should be one who take the initiative and drives things forward.
For many submissives, the attraction of kink is giving up control and turning off their busy mind, and letting someone else drive. That's perfectly understandable, but if their partner isn't naturally turned on by power exchange it can introduce difficulties into the bedroom, as one partner is left waiting for activities that never actually happen.
So, if you're the one who fantasises about spanking, that makes you the official spanking expert in your relationship. Even though you want to be the recipient of the spanks, you'll still need to take control and get things started.
Your partner may be inhibited by legitmate concerns. A fear of hurting partners is a common concern for many men. Most men are pretty nice, and very last thing we want to come across as is a brute. So clear unambiguous permission to act is essential.
Everyone has their own "arousal triggers" - the sensations and stimulations that turn them on. It's common for spanking to be a strong arousal trigger for one partner, but not the other.
This in itself isn't problem. It's not that they don't like what you love, just they don't love it as much as you do either. In every relationship, there's countless things one partner loves (food, music, hobbies), but the other is ambivalent about.
The solution is to find your partner's equivalent turn-on, then combine it with yours.
For instance, if your partner loves you to spontaneously drop to your knees and start unbuttoning, do that more often. Then make it part of the game that when you've brought them to the brink, you deserve to have your bare bottom smacked for being so naughty.
You Initiate -> Arouse Your Partner -> Spanking for You -> Happy Endings for You Both
The vital point here is: everyone is most sexually open when they're already turned on. Talking about sex is awkward when you're not aroused. It's far easier to start a spanking when you're both sexually excited.
This is due to our psychology, the brain suppresses our disgust response when we're sexually aroused, so we can engage in behaviours we'd find unappealing in any other mental state. One good example is how we see bodily fluids, smacking and slapping is another.
So turn your partner on, and don't make your partner think, make the progression towards what turns you both on seem inevitable. Tell them explicitly. Candour is hot.
For instance: "I am going to suck you. Then you are going to spank me."
Drive the scene towards what you want, and be clear about your own expectations: "Spank me. Spank me harder! I've been so naughty!"
There's no need to justify yourself, or commence a lecture on why-spanking-is-not-as-weird-as-you-think. You're simply doing the thing that turns your partner on, and ensuring the spanking you want follows on naturally.
Every time you initiate, you soften your partner's inhibitions, and increase the chances of them taking the initiative in the future. Being submissive doesn't mean you have to be passive.