How to obtain certificate no. in Form 10 IA

Section DD allows IT deductions upto Rs 125000 for disabled persons or taxpayer taking care of disabled dependents respectively. While filing ITR, it's mentioned that it is mandatory to file form 10-IA and enter the acknowledgement number while claiming deduction. According to rule 11A (pertaining to Medical authority for certifying autism, cerebral palsy and multiple disabilities and certificate to be obtained from the medical authority for the purposes of deduction under section 80DD and section 80U), a certificate from medical authority needs to uploaded (1. Form 10-IA in cases of autism/cerebral palsy/multiple disabilities or 2. Form mentioned in disability evaluation guidelines for other disabilities). I have obtained the signature from the authority but we are not sure what to fill in the "Certificate no" as we have to submit the same in IT portal as well while submitting the form. I have got the registration number of the disabled person as well as the RMC number of the authority. The medical authority is not sure what would be the certificate number, because when we download the form 10- IA, it doesn't have any certificate no. Is it some random number that will be filled by medical authority or we can use some other number. Thanks!