IOS警报未启动/单击警报转到下一页SWIFT

I have the code below working where it takes me to the login page once a user Registers their account. What I cant figure out is how to make the Alert box pop up when the account is created, and the user stays on the Register page until they click the "Login" button at the bottom of the Alert box then it redirects them to the login page. Any ideas on how to change my current code below?I have the code below working where it takes me