I would like to block all of our users from logging in except via SSO. However, I still have some cases where only I need to login with un:pw. Is it possible to allow me to bypass the blocked login? salesforce.com/?login=1 is confirmed to not work
Please follow the below steps given on Link https://help.salesforce.com/s/articleView?id=sf.sso_enforce_sso_login.htm&type=5
For a quick reference
For the users where you need to Bypass just create a new profile for which Backdoor entry is required and do not enable the SSO Enabled permission as mentioned in step 3) c. and give the My Domain URL to user to login using Salesforce Username and Password.