1. Select "Unisoc" platform from the tab menu in the upper left side of the software
2. Go to "Service" tab
3. Select your phone model in the right drop-down menu

Universal Loaders:
If the phone from drop-down list doesn't work, try generic platform loader from (Unisoc) category.

4. Turn the phone OFF
5. Select “USB (autodetect)” port
6. Press “Remove FRP” button
7. Set the phone to the special mode:
• Press and hold the "VOL -" while inserting the USB cable
• In some cases, a different key combination or connection via a test point may be required.
8. Install phone drivers (only if the phone is connected for the first time).
9. Connect phone to PC
10. The message "Removing FRP lock...Done" indicates that procedure has been completed successfully
11. Disconnect the device

If your device isn't listed among the supported models, but you have a flash file for it in the original *.pac format, you can attempt to perform a service operation.
Service such a device using loaders extracted from flash file, by following these steps:

1. Select the "Unisoc" platform from the tab menu in the upper left corner of the software.
2. Go to the "Service" tab.
3. Select the "USB (autodetect)" port.
4. Turn the phone OFF
5. Select "(PAC)" from the right drop-down menu.
6. Select “Loader selection…”
7. Press the "Remove FRP" button.
8. The program will prompt you to choose the flash file in the original *.pac format.
9. Set the phone to the special mode:
• Press and hold the "VOL -" button while inserting the USB cable.
• In some cases, a different key combination or connection via a test point may be required.
10. Connect phone to PC
11. Install phone drivers (only if the phone is connected for the first time).
12. When you see the message "Removing FRP lock...Done," it indicates that the procedure has been successfully completed.
13. Disconnect the device.

If the service operation is successful, share the log on the official Sigma forum.