If you are not able to get into CRA My Account, then there are other ways that you can check/change your direct deposit information. This CRA page has a list: https://www.canada.ca/en/revenue-agency/services/about-canada-revenue-agency-cra/direct-deposit.html
If you are going to mail in your return, then you can include a copy of the direct deposit form with your tax return. You can download the form here: https://www.tpsgc-pwgsc.gc.ca/recgen/form/inscription-enrolment-eng.html
