If you are referring to the phone number that was entered on your tax return, you do not need to update that phone number since the IRS does not call taxpayers.
If you need to update your phone number on your TurboTax account see this TurboTax support FAQ - https://ttlc.intuit.com/community/account-updates/help/how-do-i-update-my-turbotax-account-informati...
