I tested my Power Automate flow once, but I do not trust it live

This morning I finally finished the holiday request flow. When a row is added to the requests list it emails the manager, waits for approval, updates the row, and posts in the team channel. I added one fake request for myself, ran it, and everything worked. I actually said yes out loud at my desk. That was the high point of the day.

Then I went to turn it on properly and stopped. The list it updates is the real one, with 340 live rows. The email step reads addresses from a column that I know has at least a few typos and leavers in it. If I test it again, real people get emails. If the condition I wrote is wrong, it could update rows it should never touch. I sat there with the toggle in front of me and realised I had tested it exactly once, with one tidy row I wrote myself.

I tried to do it properly. I searched for how to test a flow safely and found articles about dev environments and solutions, which need access I do not have and words I do not use. A YouTube video tested a flow by just running it live, which is the thing I am afraid of. In the end I copied three rows into the list after hours, ran the flow, deleted the rows, and apologised in advance to the manager in case anything fired at her. That is not a test plan, that is sneaking around in my own process.

What I want is boring and small: a safe copy of the list, ten realistic rows including the ugly ones with blanks and typos, a way to point the flow at the copy, and a short checklist that lets me say tested, ready, switching on Monday, and mean it. The flow is good. I just cannot prove it, and until I can, it sits half-finished while I keep doing the process by hand.