send my regardsUsed to ask someone to convey your affectionate greetings or that you miss someone who is absent. ฝากความคิดถึงด้วยนะ means “send them my regards, okay?”
TH: ถ้าเจอพี่สาว ฝากความคิดถึงให้ด้วยนะ
EN: If you see my older sister, send her my regards.