You can do something similar to what I showed above. Use a variable as the trigger for starting the automation. Then the first part of the flow is a check to see if the variable is enabled. I’ll come back to why in a second. Then have that delay 2 minutes, turn on the light, delay 2 minutes, then turn it off. Then add another trigger for the light turning off.
Now when the variable is set it starts the cycle: wait, on, wait, off > repeat as long as the variable is still true