I know of no passive ways to capture Odonata. The larvae can be caught, for example, with kick sampling: https://www.nhbs.com/blog/the-nhbs-guide-to-kick-sampling Imago with butterfly net.

Try to use sweet net traps if you want o have few samples of dragon or damsel flies

I have used minnow traps and seen odonates inside. One can reduce the size of the entry holes to prevent fish predators inside the traps. However my intention was not specifically odonates. For that one used dip nets swiped across reedy margins, but since you asked for a trap, i think a modified minnow trap could work.