Dell Inspiron 15 Gaming 7567 Low Brightness Problem. Windows 10

I recently purchased a new Dell Inspiron 15 Gaming 7567 computer with Windows 10 installed.

I'm facing a low-brightness problem. Very low

And the laptop brightness dims when charger is unplugged

The computer has two video boards one integrated and one dedicated.

I have made the brightness full through the function keys, but still the screen is opaque and the brightness is very low.

15.6 "Full HD display The 1920 x 1080 resolution delivers stunning color and clarity.

Please help me to change this problem.

Thanks in advance.

Regards,

Richard