Dual channel ram Intel uhd 620

I have a Dell Inspiron 5570

I5 8th gen

Intel uhd 620 graphics cards

My laptop came stock with 8gb ram. I purchased another 8gb stick so I could have dual channel.

My bios shows I'm running dual channel with 16 gb. But the integrated graphics is only showing single channel with 8 gb total available graphics memory.

How can I get the integrated graphics to see all 16gb and the dual sticks?