The person behind the pay account alleging to be R. Kelly's former girlfriend will have to put up or shut up, because the platform they're using to make money wants hard proof they're the real deal.

There's been a lot of doubt Joycelyn Savage is behind the Patreon account ... an account which calls out Kelly, accusing him of physical abuse and forced abortions.

A source at Patreon, the company hosting the account, tells us Patreon tried Monday to verify the account. We're told the owner of the account will have a couple days to provide proof they're the real Joycelyn, or they'll be shut down.

Our source tells us the user will have to provide a government-issued form of identification to satisfy Patreon.

The account has made a significant amount of money -- we're told more than 2,000 users have paid the membership fee which ranges from $3 to $25. If the account does turn out to be fake, the money will be returned.

As for the allegations, one post reads, "I realized I was pregnant by this monster ... Eventually, I ended up getting an abortion I was forced to get the surgery done at his house."

Another post detailed an instance when Joycelyn allegedly called Kelly "babe" instead of "Daddy" or "Master" ... and claims Kelly choked her out for not addressing him properly.

As for R. Kelly's side ... his attorney, Steve Greenberg, seems to think Joycelyn is behind the account, tells us, "It is unfortunate that Jocelyn now seeks to make money by exploiting her long time, loving relationship with Robert."