Help with my auto please

It’s highly likely that’s not an actual 1000w light. Stretch period is pretty much in the books but you may get a few more inches outta her. Agree with organoman - 24/0 is a mistake. This idea I’ve seen of late that 24/0 during Veg is ok but dark period is necessary in flower for autos makes no sense either. But keep yourself a dark period for sure.

She will stretch very little now she is already flowering, and you do not want to utilise any of the usual techniques now for the same reason- she doesn't have time to recover. Maximise your yields by making sure all bud sites have light and air flow, and maximise the light especially by using an app such as photone and getting them as close to light without it being overkill.

Without a diary, there's not much we can tell you. I've grown lots of autoflowers under 24/0 and theyve been quite happy. Perhaps your lights were too close to them which means they didn't NEED to stretch to get the light? Maybe nutes would have helped give them the food they needed ... maybe the temperatures were too cold and that stunted them... maybe the pH was off... there's a lot of different things that could have resulted in your issues but without a diary, we can't know what those causes are... Good luck - next grow, start a diary!