You can. It's called paid DLC. Make a paid DLC, not a mod.
Mod are free hobbyist "products", paid DLC are for pay.

If you want to start getting money involved, I guess you should pay people too:
Those who report bugs, which are basically your Quality Assurance and Quality Control department.
Those people who talk about your pack, because they're your marketing department.
Those people who come to your defense if you fuck up, because they're your PR department.
The people who make the tools you use, because they're your support department. (And you're commercial now, you have to get commercial licenses.)
The people who make forge, because without them, your mod wouldn't even have a chance to exist.
The people who make all the modding tutorial, and whom gave you free education about modding.
The people who made Minecraft, because, yeah, you'd have nothing without it.
Reddit, which is another huge marketing department. Without it, a lot less people would know about you.
The people from all the launchers who host your mods, because they also are marketing department.

It's funny how it's always AFTER people get known, that they now want money, but wouldn't dare start out with paid stuff in the first place.
Try to make stuff for paid, without the publicity you get from making things for free, and see how far that'll get you.
But I guess you just feel too much entitled to your free publicity.
You think that if you go "for pay", everyone will go "for pay" and the whole ecosystem will turn mods into paid products?
Please, the only reason you aren't closing everything up and making it for pay is because you know that you'll be forgotten in about 2 forge version.

If you want to go for pay, do an Eloraam, and then go work on your product, and come back to us when it's done.
None of that "I'm going to monetize that thing I did, which has only been possible to do because of the support of the community".