Is Legal Heir Certificate Required In My Case.

My husband and I took a home loan in the year 2005 of Rs.15,31,000. As per papers he was applicant 1 and myself - applicant 2. We’ve been paying regular EMI’s without fail. Unfortunately, the loan was not insured. My husband expired on 11 July, 2020 in a road accident. Only 4-5 EMIs were left. After a series of mails, conversations, discussions, harassment and torture, I finally settled the loan at Rs.4,00,000 after a year in July 2021. I gave the cheque on 26 July and in return the bank has not yet given me a No Dues Certificate, Termination of Lien Certificate and Non-Encumbrance Certificate. Instead of giving us these, the bank is asking for a legal heir certificate, noc of my two children and P.O.A of the same. I fail to understand is it really necessary, I am the joint holder of the property in sale deed, I am the co-applicant of the loan, I am the wife of the deceased, I am the one who has paid the settlement amount. Please suggest what to do.