Inactive Machines Report With Primary User

I found the built in report for "Computers that have not reported inventory in last N days)" (Reports->All reports->Discovery and Inventory->Inventory->Cross-platform->Inventory Agent->Inventory Diagnostics), which works great.

I need to be able to run something like this (machines that haven't checked in last 90 days), but I also need to include username.

I've found some old threads on this (including one of mine and this one), but can't figure out how to get it work (I don't have asset management installed).  Any help would be greatly appreciated!