Cannot find 'Quick Text' channels

The limited channel visibility is caused by Case Feed being disabled in your org. Enabling Case Feed Actions and Feed Items in Support Settings will expose all available Quick Text channels. Channels available depend on which features your org has licensed.

Depending on which features are enabled in your organization, the following channels may be available:

• Email - For "Email" actions
• Event - For "Event" actions
• Internal - Works with internal fields, like on the Change Status action
• Chat - Works with Chat in the Salesforce console
• Messaging - Works with Messaging in the Service Console
• Phone - For the "Log a Call" action
• Portal - Works in a Community or Customer Portal
• Social - For Social Posts
• Task - For the "Log a Call" action

If you only see 'Chat,' try to enable Case Feed

In Salesforce Classic

1. Go to Setup | Customize | Cases | Support Settings
2. Click on Edit.
3. Select Enable Case Feed Actions and Feed Items.
4. Click on Save.

In Lightning Experience

1. Click on gear icon and select Setup.
2. In the Quick Find box, enter Support Settings.
3. Under Feature Settings | Service, select Support Settings.
4. Click Edit.
5. Select Enable Case Feed Actions and Feed Items.
6. Click Save.