The template is now available under custom templates
Select the user in the 3CX web-interface
Go to IP Phone and click Configure a Phone
Select your phone
Enter the MAC Address of your device
Click on Next
Select the interface of your PBX
Copy the provisioning link
Open the web-interface of your desktop phone
Past the above link in the Setting URL field
You need to add behind the URL /cfg{mac} !!!
<copied URL>/cfg{mac}
Do not forget to save the setting
On you phone start provisioning: Settings → 5 → 4 → OK OR reboot your phone