For Back office training get in touch with Customer success team, they take monthly training if required will schedule separate time as per availability of bank.
All UPI Operating Circulars (OCs) are uploaded on NPCI website https://www.npci.org.in/what-we-do/upi/circular In case if some circulars are not available on NPCI website then bank may check in URCS portal > Communication > E-Library .Not available ...