Impact of rcm in gstr-3b dealing with banks

Hi!

I want to clarify that my registered client providing services to the Banks and upto July 2018 client issued normal invoice with GST 18%. But now bank refused to take GST invoice and said that they will paid GST under RCM so only issue invoice without GST. There is option isn GSTR-1 for filling invoice under RCM but there no such option in GSTR-3B as outward supply under RCM and taxable supply not accept as my CGST and SGST is zero so where to show such outward supply amount in GSTR-3B??

thanks