Inbound Webex Contact Center voice routing needs an entry path and an agent distribution target. The DNIS or support number must be associated with the entry point and flow so that an incoming PSTN call reaches the proper Flow Designer logic. Inside that flow, the contact must be queued to a queue that has eligible teams or agents. Cisco's queue documentation describes queues as holding areas where contacts wait until they are distributed, and it explains that non-skill queues use team assignments or agent assignments while skill queues use skill matching. The wording in the option set refers to DNIS entries in Flow Designer; operationally, DNIS is tied to the entry point/channel and flow selection, and the flow then uses a Queue Contact activity.
Script Editor is a legacy/on-premises contact center construct, not the modern Webex Contact Center Flow Designer model. A softphone registration alone does not route calls, and a skills-only queue is not mandatory unless the design requires skills. Reference: Cisco Help, Set up voice channels for Webex Contact Center; Understand Routing and Queueing in Webex Contact Center.