Went through a toll without paying on n18 accidentally, how do go about paying?

Today I was travelling and on my way southbound on n18 I was at the toll booth in a queue for a while.

I am guessing someone didn’t have cash to pay so there were a few cars lining up and after a while, not sure how long the barrier opened I just drove automatically through. Immediately after I got through the barrier went down.

I’m conscious that there are cameras, I was on autopilot I think, in the moment I thought the barrier would stay up.

Has this happened to anyone before is there a way to pay now, or will a bigger bill come in the post?

Hopefully my post makes sense, I’m banjaxed after many hours of driving today!