Can't upgrade from 10.13.6

[Admiral Huddy]

Good evening, I'm going to confess, I know nothing about Macs, I'm trying to help a friend. We don't seem to be able to upgrade from 10.13.6 so she can use the latest version of Lr. but in the upgrade option, it says no updates available. Does this mean the Mac is end-of-support? It's about 5 years old.. Thank you

21.5-inch iMac 3.0GHz quad-core Intel Core i5 with Retina 4K display

 

[Admiral Huddy]

Thanks Feek, I'll pass that on. I managed to locate the update service through the App store and that's where it said "no updates" but I will ask them to search for Big Blur.

I'll post back.

 

[Admiral Huddy]

Worked through the app route.. Thanks, Feek