No there is not a way to add banking information for an amended return and you do not need to add it.
Even during “normal” times it takes about four months for the IRS to process an amended return. During the pandemic and due to the severe backlog at the IRS it is taking much longer—six months or more for many amended returns. Do not expect quick results from amending.
When the IRS issues a refund for an amended return it will be by check. They do not make direct deposits for refunds for amended returns. You can watch for information here:
https://www.irs.gov/Filing/Individuals/Amended-Returns-(Form-1040-X)/Wheres-My-Amended-Return-1
Not needed. They only mail checks for refunds. No Direct Deposit.
See 1040X instructions page 19 for line 22 middle of first column
https://www.irs.gov/pub/irs-pdf/i1040x.pdf
It says.....You will receive a check for any refund due to you. A refund on an amended return can’t be deposited directly to your bank account.