How do I set up my account to get ready for the second stimulus

[MissMCJ]

The IRS will deposit to the account that was set up for the 2019 stimulus.  If that account is closed, they will mail you a paper check.  Many of those payments have already been made.

[NCperson]

The IRS does not permit changes to the bank account information due to the risk of fraud.

from the IRS website: 

Where did the IRS get my bank information, and what if I need to change it? (updated December 30, 20...

Get My Payment will reflect the account information provided on your 2019 tax return, Non-Filer Registration, entered on Get My Payment before Dec. 22, 2020, or provided by a Federal Agency who issued benefits to you (Social Security Administration, Veteran Affairs, or Railroad Retirement Board).

Your payment information cannot be changed. If you don’t get a payment and you are eligible to receive one, it may be claimed on your 2020 tax return as the Recovery Rebate Credit.

My bank account information has changed or was incorrect. Can I update it using the tool? (updated D...

Your payment information cannot be changed. If you don’t get a payment and you are eligible to receive one, it may be claimed on your 2020 tax return as the Recovery Rebate Credit.