Hi Kohei Sakamoto,
Go to this create ticket link https://pstnsd.powerappsportals.com/create-ticket/ and provide the below necessary details as mentioned in this doc case-type.
New TN Acquisition – Acquire new phone numbers from Microsoft. Before creating a ticket, check phone availability in different countries
- Number Type - Select the type for your numbers. See Types of phone numbers.
- Tried to get phone numbers from the Teams Admin Center Portal - Have you tried acquiring these phone numbers from the Microsoft Teams Admin Center?
- Quantity of phone numbers required - The count of phone numbers that you want to acquire.
- State/Province - The state/province within your country/region for which you want phone numbers.
- City - The city within the state/province for which you want phone numbers.
- Office address - This is specific to certain countries only. This is the site address of your office.
- Directory listing - This is specific to certain countries only. Do you want to publish your company information with the phone numbers?
Hope this help you , If you have any further assistant, do let me know.
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