Hi there! Three months isn’t a long time to have been poling, unless you have previous back ground in fitness or have been taking class several times a week this whole time, this spin is probably not appropriate for your level. A spin like this is an adv. intermediate level spin. It requires both shoulder strength and flexibility, and while less strenuous on the body than the reverse grab, it’s still not beginner level. This is probably why you feel strain in the hand/wrist.
You might want to ask your studio for an alternative for this spin. You’ll find tons of great lessons here (in progressive order) to help you build strength and mobility for spins like this. https://www.studioveena.com/lessons
As for tips: Static spins are all about timing so understanding which is the push leg and which is the swing leg is helpful. For this spin the outside foot is the push or in this case “planted” foot and what was the inside leg is the swinging leg, giving you the momentum you need and helping you pull away from the pole. Having the feet too close to the pole when doing static spinning is common, so make sure you’re not standing too close.