If you want to remove your account on Mygov, the website of the Australian department of human services, you can easily do that in the Settings of your account.
I’ll show you below how I managed to close my profile permanently using a desktop computer:
1 Go to https://my.gov.au/ and sign in to your account
2 Click on the ‘Settings’ icon
3 Scroll down the Settings page and you’ll see a Delete account button
4 Mark the checkbox
and confirm that you wish to delete your account and remove access to member services
5 Last step: Confirm that you want to close your account
Congratulations, you’ll see a confirmation that your account has been closed.
Source (and thanks to): mygov.au