Bankruptcy discharge certificate for mortgage

Hi All. My husband and I are in the process or (hopefully) buying a house. We have passed all checks so far for the mortgage but have now been asked to send our bankruptcy discharge certificate. I know we were automatically discharged a year to the date of the bankruptcy order but I cannot find the certificates, if they were sent to us. I know I can get copies from courts for a fee which is fine but they say it takes 3-4 weeks. Has anyone else experienced this? I spoke to the insolvency service who said they can send a letter of confirmation of discharge and I have asked our broker to ask the lender if they would accept that instead. Just don’t really want to delay things for another month possibly. Has anyone else used a letter of confirmation?
Thanks