To create a Google Chat notification webhook, make sure you're logged into your g-suite account instead of your personal e-mail. Personal e-mail addresses cannot create webhooks in their spaces.
Start by heading over to https://chat.google.com/ and make sure you're logged into your g-suite account. Make sure you have a space created, if you do, click that space and press the arrow down and press "Manage webhooks":
This will open up a new modal where you can create the webhook:Inside the avatar field, you can fill in an avatar you'd like to be displayed, we offer a default one for you if you like: https://ploi.io/ploi-192x192.png
After creation, you'll get the URL by clicking the copy button:
After grabbing this URL you'll be able to enter this inside your Ploi profile under https://ploi.io/profile/channels: