Hello, @sa14. 

Thank you for posting here in the Community. In QuickBooks Online, you'll need to turn on the location feature and create a class to assign multiple distributors.

 Here’s how:

1. Go to the Gear icon on the right side. 
2. Click Account and Settings, then select Advanced. 
3. Under Categories, turn on both Location and Class. 
4. Tap Save, then hit Save and close.

After that, let's add a location by going to the Settings ⚙️ icon, then choose Locations underneath the All Lists tab. And click New to enter a location, then tap Save and close. See the screenshots below:

Once done, let's create a sample invoice by going to the Plus icon to see how it works in the invoice template. I've attached a screenshot for your reference: 

Additionally, you can always run Sales report from the Reports menu. This way, you can check and print the particular locations you've set up. Simply hit the Customize button on the upper right side, then choose a specific address under Filter. Please visit this article: Run reports by class.

I've got this screenshot for your visual guidance: 

You can also use a third-party app as by Fiat Lux - ASIA mentioned above. Don't hesitate to leave a comment below if you have follow-up questions. I'm always to help. Take good care.