Managing personal Outlook.com account settings, security, and privacy
Thank you for the clarification.
In order to change the recovery phone number, you will need to regain access to the account first.
Since you do not have an active 2FA and no access to the security info, I'm afraid the only way to recover/verify the account is through the account recovery web form: https://account.live.com/acsr
You'll need to keep trying until you're verified by Microsoft, and you can do this up to 2 times every 24 hours.
If your Microsoft account recovery request was not granted, please review this link for tips on improving your chances of a successful recovery: https://support.microsoft.com/office/dc56c3e3-dff0-4ed5-8edb-60290eea6b53
Please be advised that Microsoft Support will not be able to grant you access to your account.
Thank you for your understanding.
Best regards,
Darhyl