Hi, does anyone know why my plants leaves are curl...

There must have been a Nitrogen stack up in the soil during veg. Even though you don't give too much N to it, during stretch this can happen for ruderalis dominant autoflowers,talking from my experiences with autos recently.Shit genetics play a big role on this one. Plant seem to have stretched a lot, unnecessary stretch,look at the distance between nodes. This plant doesn't like N at all and highly stacked up N caused it to stretch like crazy and have clawing leaves. This is not an overwatering problem. You seem to go organic on this one, I don't know well about what you could do in organics,I think there will still be N in the soil throughout.Excessive N might cause some other elements to lockout like calcium and potassium.Just try to focus on bloom elements (potassium & phosphorus) and watch for any calcium need.This is what I would do if that was my plant in an organic soil grow.If that was synthetics, I would cut off N immediately,do a good flush and increase bloom dosage.But this plant will likely bring 5-6 gr of flowers at the end.Genetics play a big role in growing,trust me.This plant should have been bigger and vigorous by now.Many seeds are sold nowadays without stabilising,you can find seeds with highly,mostly ruderalis background like this one,instead of having "purple lemonade" background.They used to say "autos are still weak but are being worked on and will be better" a decade ago.Autos got better from the middle of 2010s and now it's a selling game where names play a huge role.Just keep on growing,play with your plant and you'll learn about it,you can see it as a game from now on.Cheers