Changing the Company name on the Account and Settings section won't appear as your Legal name on payroll settings. Since your business info on that page is one that the customer sees on sales forms and invoices.
In QuickBooks Online (QBO), you can use a different Company name. But for the Legal name, it should be the one that the IRS has on file for your company.
To know how to check the Legal name on all your forms, here's how:
Click the Gear icon at the upper right hand.
Pick Payroll Settings.
Under Taxes, select General Tax Information.
Go to the Filing Name section to verify the Legal name.
Take a look below articles for more idea about changing company/legal name in QBO: