The seventh method :
Create an event on the group and adjust the settings and publish it to the group, for example, I create an event with a 50% discount on products, for example, who will resist such an offer?!!
The eighth method :
It is a professional method, but I have seen some foreigners who have applied it. It is known as the Vip Group. The group here has a monthly subscription that you specify with the members, let it be $10 for example, especially if it is an educational group, in which you train, educate and provide explanations to people.