What is the ruling on taking 10% in exchange for paying a government bill from the institution's account on behalf of the customer, given that the customer pays the original value of the bill from their own account?

We understand that the transaction is an agency for a fee, which is permissible. Sheikh Yusuf Al-Shubaili was asked about taking a sum of money in exchange for paying government service fees (passports, fines, visas). He replied that "there is no harm in that, because the fee you take is not in exchange for a loan or currency exchange, but rather for the service you provided to the client, which is the delivery of money." However, regarding the fee being a percentage of the amount, there is a difference of opinion among scholars.