I bought an 2019 iMac computer this year. I am unable to get the keyboard backlight to work. Can anyone help

And a third vote: I've never seen an iMac with a lighted Apple keyboard. There may be some after-market ones but nothing Apple-branded.

Here is a third-party option from Matias:

http://matias.ca/aluminum/backlit/

The iMac keyboard is not backlit.

Yes, Stedman is sure, as am I.

It is not a backlit keyboard.