Create a callback secret

<Info icon="fa-light fa-lock" className="permission-callout"> <div className="permission-callout__header"><span className="permission-callout__title"><span className="permission-callout__label">Required permissions</span> <span className="fern-docs-badge small blue subtle rounded-full permission-callout__beta">Beta</span></span> <span className="permission-callout__learn-more">[Learn more](/developers/api-guidelines/permissions#how-permissions-work)</span></div> `CallbackSecret` + `Create` <div className="permission-callout__roles"><span className="permission-callout__roles-label">Roles:</span> <Badge intent="info">Administrator</Badge> <Badge intent="info">User</Badge></div> </Info> Creates a new secret that may be used by API callbacks. When an `api_secret` is assigned to a Service Profile with an API callback, API requests towards this URL will contain an `Authorization` header with a JSON Web Token. The `api_secret` is used as the **Signing Key** of the JWT.