To set the ATO Credential in the current year of HandiTax:
Open HandiTax, then go to Lodgment, Set ATO Credentials.
Click the radio button Access ATO Gateway or ATO Credential Authentication.
Under Browse for Key Store file, click the ellipsis to select, and then click Open.
From the Select Credential drop-down menu, select your credential.
Enter your keystore password.
Click Ok.
Restart HandiTax for the changes to take effect.
When you next log in, attempt a prefill or lodgment to check that the credentials function successfully.