1. Install the module
- Extract the module archive which you downloaded from the client area.
- Upload the module to your WHMCS installation.
- Go to the WHMCS Admin backend, click on Setup → Addon Modules and activate the module.
- Click on Configure and enter your license key.
- Set the option which meets your requirements.
- At "Access Control" select nothing.
2. AutoAuth Key Configuration
If you did not defined an AutoAuth key in your WHMCS installation, then open the configuration.php file, which can be found at the root directory of WHMCS, and add following code at the end of your file:
$autoauthkey = "secure_string";
Replace "secure_string" with a random string.
If no key is defined, the auto login will not work. In that case an error message get logged into your Activity Log which tells you to add a Auto Auth key.
3. Enable AutoAuth in WHMCS (only WHMCS 7.10 or higher)
Since WHMCS v7.10 AutoAuth must be explicitly enabled in the WHMCS settings. Navigate to Setup > General Settings > Security and set the value of the option "Allow AutoAuth" to "Enabled".