You can only disable password authentication if you set up your account to use single sign-on credentials. Otherwise, password authentication is required and cannot be modified.
Sign in to DigiCert ONE.
Navigate to the Manager menu icon (top-right), select Account.
In the left navigation menu, select Accounts.
On the Accounts page, select the Name of the account.
On the Account details page, in the Sign-in settings for all-account-access users section, the Password only pencil (edit icon).
On the Manage password only page, select Disable standard sign-in (for accounts with alternate sign-in methods configured).
Select Save.