Iran have very much been at arms length with it all, but it’s all but certain they’ve had some hand in it. They’ve been very careful so as not to be easily held accountable, though. There are no direct ties, so you couldn’t prove it beyond reasonable doubt, but on the balance of probabilities Iran most likely was involved.
I don’t have first hand sources or the actual videos, but this covers the paraglider training: https://edition.cnn.com/2023/10/12/middleeast/hamas-training-site-gaza-israel-intl/index.html
This one says it was Hezbollah who trained them in Syria and Lebanon: https://www.telegraph.co.uk/news/2023/10/13/hizbollah-trained-hamas-paragliding-terror-attack-israel/
The bit about meeting with Iran and Iran approving it wasn’t an official statement, but was given by “sources familiar with the operation”: https://www.nytimes.com/2023/10/13/world/middleeast/hamas-iran-israel-attack.html
The WSJ reported from “Hamas sources” that Iran approved the attack on Mon 2 Oct: https://www.wsj.com/world/middle-east/iran-israel-hamas-strike-planning-bbe07b25
Iran have very much been at arms length with it all, but it’s all but certain they’ve had some hand in it. They’ve been very careful so as not to be easily held accountable, though. There are no direct ties, so you couldn’t prove it beyond reasonable doubt, but on the balance of probabilities Iran most likely was involved.