There are many different ways to monetize your game and this is just a short tutorial on the different methods of doing so.
I feel that when you have an in-game currency people are more likely do purchase your products than if the player just gets a prompt to get it with robux. When they want to get an item and they see they don’t have the amount of currency needed, they’ll just purchase the amount of their choosing from the currency shop.
Offer a starter pack that is time limited and contains multiple items at a good deal. Instead of buying currency and going through a shop selection, they can, for example, buy the starter pack for 250R$ and get a customization package, a weapon and some in-game currency.
Give the player an option to get a currency boost that lasts a limited amount a time and has an unlimited amount of uses (use a DevProduct).
Please note that there are various tutorials for everything I wrote here. You can find most of them doing a simple google search.
That’s all for now, feel free to leave feedback below.