How can you forget a wi-fi connection you've used

I have used a wi-fi connection that requires a password. But it is flaky and I now have my own wi-fi to use. But occasionally my computer still uses the first wi-fi. If I could make my ubuntu forget that password, it wouldn't use try the flaky connection anymore. (I am using Ubuntu 18.04.05 LTS)

Solution 1:

I suggest a GUI alternative to remove the connection. I presume you are using the GNOME environment.

Go to: the System status area; Click the Wifi connection; Go to WIFI settings from the drop-down; Click the icon that resembles three dots arranged vertically; Select known Wi-Fi networks; Select the Wi-Fi connection and Click 'Forget' to remove the connection.