No, you cannot repair a sidewall puncture on a tubeless tire. The sidewall of a tire is critical to supporting the weight of the vehicle and structural integrity while driving. When the sidewall is punctured, it weakens the tire and flexibility, making it unsafe to use even with a patch or plug. Unlike tread punctures, the sidewall is not designed to handle the same repair techniques due to the constant flexing and pressure the area endures. Trying to repair a sidewall puncture can cause further damage or a blowout while driving. For your safety, it’s best to replace the tire altogether if the sidewall is compromised. Always consult a professional mechanic to see if a damaged tire can be repaired or needs to be replaced. Safety over cost when it comes to tire damage, especially on the sidewall.