Question about MuckRock services: payment to government

If MuckRock makes a public records request to a local government and the response from the government indicates that a payment is required, how is this processed? Or in other words, if the government says it will cost $100 to provide the records would I pay the $100 to MuckRock and then they would make the payment to the government or would I pay the government $100 directly? If I must make the payment, presumably by check, then I would no longer be able to remain anonymous to the government, correct? To remain anonymous it would be helpful if I could send the payment to MuckRock and then they make the payment to the government under their name. I’d even pay extra for this option. Or is there another way to make a government payment while remaining anonymous?