To create a webhook, your role will need permission to Manage Webhooks and to access the project you wish to create a webhook for.
Setting up a webhook
In the project you wish to create a webhook in, go to the Integrations tab
Then the Webhooks tab
In this section, you can add a webhook by entering the webhook URL, and selecting the event you wish to subscribe to, then clicking "Create new webhook".
Once added, the webhook will send a JSON payload of data whenever the subscribed to event is fired.
Existing Webhooks
Any of your existing webhooks for the project will be listed under Existing webhooks