Thank you for posting here in the Community space about updating your account information. I can help you update your phone number in QuickBooks Online.
You can make changes to the account details directly within your QuickBooks account. There's an option to access your Intuit profile in the upper-right corner next to the Cogwheel icon.
Here's how:
Sign in to your QuickBooks account.
Click your profile icon in the upper-right corner.