Welcome to the QuickBooks Community. I'll ensure to share details about setting up language and region in QuickBooks online. Then, how it works to the system.
The supported languages in QBO are English, Chinese, Français, Italiano, and Español. You can set it up by going to the Account and settings. You can select the Advanced tab and you'll see the Language section to change the desired language.
Go to the Gear icon. Then, select Accountsand settings.
Choose the Advanced tab and go to the Language section.
Select the pencil icon to edit. Then, choose the desired language from the drop-down.
Hit Save and Done.
You also have the option to change the language in QuickBooks Online using the language settings of the browser. Please click this article to view steps on how to perform the process: Change language in QuickBooks Online.
However, if you're unable to perform the steps shared above, I recommend logging in to your QuickBooks account using a private browser. This is to rule out the possibility of a webpage issue, and private browsing doesn't store local files or cache.
Use these keyboard shortcuts based on the browser you're using.
For Firefox or Microsoft Edge, press Ctrl + Shift + P.
On the other hand, the account’s region is set by the region’s website in which the subscription was made. That said, there isn't an integrated way that'll let you change the country of your subscription. You'll need to create a new QuickBooks account by choosing your country. Before that, I suggest canceling first the current QuickBooks account to avoid double billing.