I think the best you can do in is to talk directly with your boss and express your concerns.
You seem to already have delivered value to them, so you are in a good position to tell them what you would like to happen or how you feel about it.
If they are a good manager, you’ll get a good response and things will improve. If they are not, you wouldn’t want to work for them for much longer I guess…
Agreed that direct conversation is the only good approach.
But I also want to mention: have their been any actual outcomes from this project, or is the board just "excited about it"? Has there been revenue realized? If you ask for "credit" before there is real outcomes, you are basically asking for the boss to name drop you to their boss. While that's not _egregious_, personally I would wait until there are business outcomes as collateral to ask for real recognition: a promotion, more responsibility.
You seem to already have delivered value to them, so you are in a good position to tell them what you would like to happen or how you feel about it.
If they are a good manager, you’ll get a good response and things will improve. If they are not, you wouldn’t want to work for them for much longer I guess…