Is SMTP password different from the account login password?

Yes, When you set your login password for the first time using "Set password" link the SMTP password also changes to the same value as your Login password. However, you have an option to set these differently.

You can refer to below link to check your current SMTP password where you also get an option to change the same.

https://emaildocs.netcorecloud.com/docs/how-to-retrieve-my-smtp-password-from-pepipost-panel