If you’ve forgotten your WiFi password, Mac computers have a quick way to find it using the Keychain app.
Open the Keychain app on the Mac. The app is located in the Applications> Utilities folder.
You can also open it by searching for it in Spotlight.
In the left panel, look for System. Click on it.
Locate the name of your Wi-Fi network on the right side. If you do not know the name of your Wi-Fi network then click the Wi-fi icon on the Mac Menu bar on top and the name that has the checkmark next to it, is the network you are currently connected to.
Double click the name of your Wi-Fi network and a pop up window should open up. Check the box next to ‘Show Password’ and the system will ask you for your Mac login (not the Apple ID). Once you enter that your Wi-Fi password will be displayed.