>>88025713Complement an article of clothing or something about her hair/makeup, don't say something generic like she's cute, woman unironically hate that. If she's got her hair styled or dyed than that's an easy icebreaker, just be prepared to say something else after she says thank you. If you start the conversation it's your job to keep it going, woman can smell fear a mile away.
If you're worried about your confidence, just put yourself in the headspace that you're a married man with kids and you're just trying to be polite without any motives, also try to keep your body language relaxed, hold you phone in one hand to keep it grounded so you're not nervously cracking your knuckles or something while trying to talk.