As per this article Two-factor authentication for Apple ID - Apple Support
If you're signing in and don’t have a trusted device handy that can display verification codes, you can have a code sent to your trusted phone number via text message or an automated phone call instead. Click Didn't Get a Code on the sign in screen and choose to send a code to your trusted phone number. You can also get a code directly from Settings on a trusted device. Learn how to get a verification code.

You are clicking on call me inspite of getting text me , an automated call will come to your trusted number ( it could be your land line number or mobile number what ever you have added ) and speaking verification code for your 2FA account .