USCIS, the Immigration Office, announced that starting from October 1, 2023, it will no longer require a biometric service fee, i.e., a fee for fingerprint appointment, for the I-539 form. This form is used for nonimmigrant status change or extension applications.
If your application was submitted before October 1, you will still need to attend the biometric appointments. If you mistakenly paid this fee after October 1, and the $85 was paid separately from the application fee, USCIS will refund you the $85. However, if the fees were paid together, your application will be considered invalid.
I remind you that the immigration process is difficult and complex, so it is very important to take each step carefully and consult with an expert lawyer in the field.