Screen scaling on 10.14.5

[pete....]

Hi,
I have a MacBook Pro connected to a Dell D6000. The monitor is a 4k Samsung. In display settings, I can change the screen resolution but I can not configure scaling in the same way I can on laptop display. I would like to run the external monitor at its native resolution of 3840x2160, but scale up the fonts to make it easier to work on.

Is there a way to do this?

Attached are screen shots of the display settings for the laptop display and external display.

Thanks
Pete