I have a Intel i3-8130U processor and Windows 10 and 4GB ram and Intel UHD 620 Graphics
Total Available Graphics Memory=2131MB
Dedicated Video Memory=128MB
System Video Memory=0MB
Shared Video Memory=2003MB
You don't need change any thing. Your settings are correct. The amount of Video memory is controlled by Intel Driver and Windows. Please read the explanation here. In order to have more Graphics Memory you should buy more RAM.