I'm in the Normal Mice tab, not the keyboard tab. I should have provided a screenshot. As for "why not Logitech...", I'd rather use BTT as opposed to two different pieces of software. Second, Logitech doesn't allow for app-specific key commands. This is therefore about focussing on BTT.
That's the part I missed. I was in the keyboard tab. I should have known it was from the Logitech Gaming Software, that it would be sent as a keyboard sequence.
Problem solved. Thank you. Have a nice day.