Throughout the experience you will see that there is the concept of State for your Channel. You might have a Channel configured but you do you not want to process any events or receive data from that that third-party system via the Webhook you've installed.
You can see the State of the Channel in two places:
The Channels home page of your Flow Plus experience
See State Column Header and row valueas Enabled
Within the Channel-specific management page.
See Enabled label next to the Channel Name
Enabling and Disabling Event Flow
To Disable from receiving event data or Enable your Channel to receive event, simply click on the Disable or Enable button on the Channel-specific management page.