Hello @semaja ,
I would recommend to use "<LocalizedString ElementType="UxElement" StringId="button_cancel">Cancel</LocalizedString>" in "SelfAsserted-ProfileUpdate" in localization policy.
This will give the user to cancel and take user step back to choose email as MFA option.
Also please try extension policy as per https://github.com/azure-ad-b2c/samples/blob/master/policies/mfa-email-or-phone/policy/SignUpOrSignin_PhoneOrEmailMFA.xml , where user will have option to choose MFA via email or phone.
Please do let me know if you have any queries in the comments section.
Please "Accept the answer" and "Upvote" if the suggestion works as per your business need. This will help us and others in the community as well.