Firebase Authentication Issue - Button only showing as IBAction and not IBOutlet

I am following the ‘Firebase Authentication Tutorial 2020 - Custom iOS Login Page (Swift)’ tutorial on YouTube and have got to around 29:30, but when I link the ‘Sign Up’ button to the code it is only able to be IBAction as opposed to IBOutlet, which it should be. Does anyone know how to fix this? I have included an image for reference.

Try Right Clicking on the “Sign Up” button and it should bring up a Black box which shows the outlets attached. Scroll down to referencing outlets (yellow highlighted) and if there is nothing attached then click the little dot next to “New Referencing Outlet” and you can drag that to your ViewController.Swift

Hopefully that works.