Phone Dial-in Contacts

Hello,

If you read some of the associated links for the support article you linked  it looks like you need to purchase  an Audio Conferencing plan add on for this ability to be enabled.

Prerequisites

• Account owner or admin privileges
• Host of meeting must have dial-in numbers for participants to join by phone

https://support.zoom.com/hc/en/article?id=zm_kb&sysparm_article=KB0064472 

Prerequisites for joining a Zoom call by phone

• Host account is Pro or above (subscribed to the Audio Plan add-on for toll-free phone numbers)

For joining a meeting or webinar by phone:
Host account allows participants to join by telephone (Audio Type user setting)

• For joining a scheduled meeting by phone:

Host's scheduled meeting allows participants to join by telephone (Audio setting in schedule meeting settings)

For joining a webinar by phone:

• Host account allows participants to join webinars by telephone (Allow webinar attendees to dial in through above numbers account-level setting)
• Host's webinar allows participants to join by telephone (Audio setting in schedule webinar settings)

Regards

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