A Microsoft file hosting and synchronization service.
Hi Syakila,
I had the same problem adding my mobile number in my Microsoft Account. What I did is I contacted Microsoft Support. You can talk to a Microsoft support agent by chat or phone on the "Contact Us" page.
1-Access the Microsoft contact us at this link.
https://support.microsoft.com/en-us/contactus
2-Click on Windows and then click on "Get Home support"
3-Write a brief description of your request or issue in the box then click the "Get Help" button.
4-Click on the "Contact Support" button located at the bottom of the page. If you are not logged in, you will see "Sign in to Contact Support". Log in to your Microsoft account.
5-Select your Product or Service. Choose a Category then click Confirm
6-Lastly, choose a support option
I hope this information helps.