installtointernal is not officially supported.
Newer devices can use ceemmc, which is actively developed and supported.
Unfortunately it isn’t working on your device.
CE on X96 Mini is being used by some users here and should work flawless.
Please try it with gxl_p281_1g.dtb or gxl_p281_2g.dtb (depending on the RAM being used in your device).
Also take a look at the following thread: