I have 2 UITextFields, one of them for Login and the another for the Password.
UITextFields
Only if the Login is \"succesful\", I want to perform the Segue
Segue
You need to drag the segue from the overall UIViewController to the next UIViewController, i.e. you shouldn't specifically connect the UIButton (or any IBOutlet for that matter) to the next UIViewController if the transition's conditional.
UIViewController
UIButton
Like so: