as a kind of semi apologetic interjection, right? like "ope! look at the time!"
That's pretty much it. Although it can also be used like a less aggressive "hey!"
Nearly bump into someone in the hall? "Ope!"
Someone examining the spices for 5 minutes when you just need to grab the salt? "Ope, scuse me, just gotta sneak by ya there."
Etc.
Having spent some years in the south, clearly "errinj coke" is a fanta orange, or Sunkist if you're lucky.