@bastionhd Supported wrist curls and supported reverse wrist curls are all you need. Other exercises do similar things, but the stability added by wrist support should theoretically increase muscle recruitment. Working the wrist muscles simultaneously rather than alternating also makes sure you're not gassing out the wrist on things that are harder but aren't any more effective.
As long as your volume isn't high and you ease into it, you could realistically alternate between wrist curls and reverse wrist curls at the end of EVERY session and be totally fine. Unless you've got some sort of issue, forearm recovery should be one of the fastest in the body.
Don't do heavy wrist curls. It's riskier (marginally), but more importantly, less effective. Forearms respond best to 20-30+ repetitions. Rest-pause can help time efficiently help maximize your gains.