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It is referring to the console of the browser you are using. So in Chrome you would hit f12 and you get access to the developers console in the window that opens.

A word of warning though. Make sure you fully understand what a piece of code is going to do before running it. I don't mean read what the people posting it say it does, but understand the code itself. The people on this forum are generally pretty good and I would say anything Dan Diebolt posts or has on his QuickBase reference pages is legit and will not harm your records. However, sometimes the code is old and doesn't work exactly as you would expect it to or things have changed over the years. So it is still a good idea to at the very least test the code on a copy of the app that you make. That way you are not going to cause a big problem if it fails.

If you cannot get it to work or are not great with code you can always explore the way QuickBase Coach said he could do it. They generally prefer more native solutions so if you want to do it without code they can get you there.