Money is a metric of external success.
If money (i.e. the external, material success) played no part and it was all about time you could just retire to a cabin in the forest to have all the time and none of the money till the day you die. That's because you already have time and you get more every day.
But happiness and money aren't necessary orthogonal. If you're unhappy then money can't make you happy but if you're happy, money can amplify that and make you more happy.
Money first gives you more options to do what you want but ultimately it gives you power. And power gives you leverage to change the world: first your own world and then the whole world. In other words, with money, you can do more and you're happier for that.
However, that doesn't work if you don't know what you want and you only want things to become happy.
You first need to be happy with what you have in order to be in the position where you can want more. Then you can use money the right way, almost as a beam of power to change things around. But in order to be equipped to do that you need to be on clear yourself: you already need to be happy not because of money, and you can no longer need the money to validate yourself at that point. You must have had accepted who you are because if you haven't, you can't be happy either.