The signin 2SV SMS verbiage used by Chase is: "Chase: DON'T share. Use code 12345678 to confirm you're signing in. We'll NEVER call to ask for this code. Call us if you didn't request it."
I assume in the case where the customer initiates the call and support is verifying their identity via SMS, they use different text (i.e. not "to confirm you're signing in"). Otherwise, that'd be pretty ridiculous.
My reply involved the effort of sending a test message from my Chase account, to capture the exact text used. If you want people to engage with you in good faith, you should put similar effort into your replies, rather than just use Reddit-speak for "I think you're wrong."
I assume in the case where the customer initiates the call and support is verifying their identity via SMS, they use different text (i.e. not "to confirm you're signing in"). Otherwise, that'd be pretty ridiculous.