Prerequisites

Set up permissions that are required to run the durable streaming samples.

You must have access to a Developer Edition org and have the “API Enabled” and “Streaming API” permissions enabled. The “API Enabled” permission is enabled by default, but an administrator might have changed it.
If you are not already a member of the Lightning Platform developer community, go to developer.salesforce.com/signup and follow the instructions for signing up for a Developer Edition organization. Even if you already have Enterprise Edition, Unlimited Edition, or Performance Edition, use Developer Edition for developing, staging, and testing your solutions against sample data to protect your organization’s live data. This is especially true for applications that insert, update, or delete data (as opposed to simply reading data).

To verify that the “API Enabled” and “Streaming API” permissions are enabled in your organization, from Setup, enter User Interface in the Quick Find box, then select User Interface.
Note
To receive notifications, the logged-in user must have “Read” permission on the StreamingChannel standard object.
To create and manage notifications, the logged-in user must have “Create” permission on the StreamingChannel standard object.
To save the Apex class, the logged-in user must have the “Author Apex” permission.
To save the Visualforce page, the logged-in user must have the “Customize Application” permission.

Streaming API Developer Guide