When you made your visa application, you will have nominated a local Post Office to collect your BRP from.
The decision letter from UKVI contains the location for collection of BRP, this is normally a local Post Office.
If student went to Post Office and there BRP was not there, then we would suggest the student to visit the Post Pffice again after a couple of days.
Students can visit UKVI for more information here: Biometric residence permits (BRPs): Getting your BRP if you applied from outside the UK - GOV.UK (www.gov.uk).
Students are also requested to upload a copy of their BRP (Front and back) to complete their ‘Right to Study Check’.
If your Student visa permission is entirely digital, you will not have a physical BRP.
For more information please see: https://www.mmu.ac.uk/study/international/when-you-have-an-offer/secure-your-place/when-you-arrive/collect-your-biometric-residence-permit