Can’t find brightness adjustment icon!!
Lou Hall: on which specific Kindle, Fire tablet, or Kindle app?
Answers can vary, and, if you have a basic Kindle there is no lighting on the device to allow a brightness control.
I'm being extremely clever up here and there's no one standing around looking impressed. What's the point in having you all? - Dr Who
Here are the help pages that you can use to identify which device you have...
Help & Customer ServiceAmazon Device Support ›
Which Fire Tablet do I have?https://www.amazon.com/gp/help/customer/display.html/?nodeId=201263780
Which Kindle E-reader do I have?https://www.amazon.com/gp/aw/help/id=201263790
I have a Kindle Voyage and am asking the same question... how do I adjust the backlight?
Amazon has wonderful Help pages.
Here's one re lighting for your Voyage:
Here is the main Help page for your device:
from your home screen, look for the gear icon then look for brightness