If you want to list the all the accounts username using SSH then run below command.
whmapi1 list_users
It will show list of all the accounts hosted on the server. It will show output like below:
[root@ ~]# whmapi1 list_users
---
data:
users:
- abcded
- dfgdfgdfg
- dfgdfgdfg
- rtytryrty
- gfhjgfhj
- fghfghfgh
- iopuiopyuio
- ghjkhjkhjk
metadata:
command: list_users
reason: OK
result: 1
version: 1
[root@ ~]#