The HTTP connector is accessed from the Connectivity tab of the design component palette:
This connector is used to first configure an HTTP connection to establish connectivity through HTTP or HTTPS, including RESTful web services. Once a connection is established, you can configure one or more HTTP activities associated with that connection to use as a source or target within an operation or script, including GET, PUT, POST, or DELETE, or custom activities. In this way, the HTTP connector allows you to consume REST endpoints as part of an operation.
Whether the activity can be used as a source or a target in an operation or a script depends on the specific web service and the request and response structures, if present. For more information about what determines if an activity can be used as a source or target, see Parts of an Operation in Operation Creation and Configuration.
Together, a specific HTTP connection and its activities are referred to as an HTTP endpoint. Once a connection is configured, activities associated with the endpoint are available from the Endpoints filter: