I was reading the script of the TV series called Blacklist:
Paramedic: I’ve never worked with any of these people before. I was told to be on standby for a 48–hour window. They said I had under four minutes to pull a chip from your neck.
Red: Who told you you had four minutes?
Paramedic: The people who paid me.
Red: How were you paid?
Paramedic: Cash, at a drop.
Red: Where?
Paramedic: It was always a different place, different locations. They picked me up in an ambulance. I didn’t even know where we were going.
In the bold sentence, I'm wondering what does at a drop mean? I saw in the dictionary that a drop of something means a small amount of something, but I don't think that's what's meant here.
I've also asked from ChatGPT, which gives the following answer, which I suspect may be wrong. Since I couldn't find this usage on the internet,
The phrase "at a drop" refers to a predetermined, often secret, location where an exchange takes place. In this context, it means the paramedic was paid in cash at a specific place arranged beforehand, likely to maintain discretion and avoid detection. This term is often used in situations involving clandestine or undercover activities.