What’s causing my plant to do this?

This is my first time growing and things have been going almost perfectly so far but sometimes my plant will just look a little droopy. I’ve also noticed a tiny amount of folding almost like a canoe. It’s been growing super fast since I put it into flowering so it seems healthy, any ideas? Thanks

It’s been really hot the past couple days so maybe it’s under watered?

Was that taken in the evening? If so don't worry plants will often relax as the sun starts to go down. If that's the case she should be perked back up by morning!

at the very most your soil looks like it could use more drainage but I could be wrong as I can only catch a glimpse of your medium. But overall the plant looks happy and healthy... how much do you water? Usually drooping plants means its overwatered but could mean a few other things at well. But since your plant looks super healthy I would agree more so with @farmingfisherman

Thanks for the swift reply. I took this at 12 in the afternoon. I noticed it was a bit droopy once I took it out the cupboard I’m using to give it 12 hours darkness. I keep the door slightly open and have a fan blowing in to avoid it getting stuffy or too humid. It’s been 5 days and it’s been fine until today. I live in the uk so I’m limited to what’s available to me.

I’m also watering every 2-3 days and using about 1 to 1.5 litres of water depending on the amount that comes out of the bottom once I’ve poured half in. The pot has pretty good drainage so I don’t think thats the issue.