@Jaffar Sadiq Thanks for reaching out to Microsoft Q&A, apologize for any inconvenience caused on this.
As mentioned in the documentation, Trial Phone numbers are available for the subscriptions with billings address in United States only.
For other geographies you need to purchase the phone number. Purchasing the Phone numbers is based on the subscription eligibility.
I hope the answer helps. Please let me know if you have any further queries. Please accept as Yes if the answer provided is useful, so that you can help others in the community looking for remediation for similar issues.