In order to register an BM account on Facebook, you will need a strong and aged Facebook Social account, make sure to warm it up every day, login with the same IP, build trust with the same login device, and do not violate any policies, especially spamming.
Even when you have successfully created a BM, it is not usable until it is aged for months, it maybe going through the process of being restricted for no reason, then reinstated. Its ad account(s) must also be aged and if it go through the payment method adding process, its spending limit will still very low (from 50$). You will need to regularly building your BM in order to increase its spending limit.
It is a time-consuming work. You can easily mess the whole process just by getting restricted at 1 step. That is the reality of creating a BM by normal method.
As some one mentioned above, if you want to make BM the "modern" way, you will need to learn how to code yourself, which is another time-consuming work, or buying the code from other to make BM (but the code can only work for a period of time and sometimes FB raided all BMs registered via that specific code), or, the easiest way, find some one on the Market place to buy their BM.