To view all accounts within WHM, you can follow the steps listed below.
1. Log in to WHM and navigate to the List Accounts section:
2. This will take you to a screen with an account list of all domains on the server:
From here, you can modify and manage accounts, as well as being able to directly log in to their cPanel accounts.
You can find more information about what you can do on this page at the following link:
https://docs.cpanel.net/whm/account-information/list-accounts/