How can I transfer online store ownership to a new account?

[BHCDesign]

Our marketing manager has ownership of our store which she set up and she no longer works for us.

I have her log-in details but it asks for her 6-digit authenticator app code which I do not have access to.

I also have my own account that I can log into, but I do not have full ownership access.

The reason I need full access is another of our users who has her own log-in can no longer view financial information. Her permission is set to financials, but I believe one of the payment methods we were using is possibly no longer supported, but without ownership access, I cannot check/modify this.

How can I transfer ownership to my account or bypass the authentication app and set it to SMS authentication like my account has on the marketing account?