What does the agency authorization of WeChat business mean?

Specifically, you want to be an agent of a certain brand, but the source of goods must be sent to you by them, but if you want to have the source of goods, you must join them, that is, they will give you an authorization, which is legal, so you can sell the products of the merchants aboveboard, because the trademarks applied by others cannot be promoted by their names or products without authorization.