Go to Policy > Password Policy, from the left navigation bar.
Under Password Settings section, set a value for Password history. The value for password history cannot be less than 0 or more than 10.
This value indicates that the last 'n' passwords, cannot be same as the new password you will set for customer admin or its end users while changing or resetting password.
Scroll down to the end of the page and click on Save Settings button to save the configurations.
e.g. :
If the password history is set to 3 for a customer admin, when an end user's password is changed (e.g., to "Password1"), this is stored in their password history.
When the password is changed for the first time after enabling password history, it must follow the password policy and cannot be the same as the current password. For example, the new password could be "Password2."
On the second password change, the new password cannot be "Password1" or "Password2," as they are the last two passwords used. The new password must be different and follow the password policy, such as "Password3."
For the third password change, the new password cannot be "Password1," "Password2," or "Password3," as they are the last three passwords used. The new password must be different and meet the password policy requirements, for example, "Password4."
On the fourth change, the new password cannot be "Password2," "Password3," or "Password4." However, "Password1" can be reused since it is no longer among the last three passwords used.