How to release an iOS app as worldwide which was release with Italian as the language in the first version?

1. I am using Apple's VPP Store to release my app to specific customers.
2. The customer whose apple id I added for the VPP is an Italian Apple Id.
3. Also I made the default language as Italian.

But the issue is a french user is unable to install the app when he clicks a link generated for him.

I think the issue is I made the Italian as default language. So how can I release the app as worldwide now? Or is it because I released the app with the apple id of an italian customer for the Volume Purchase Program Customers?

Please clarify the issue and tell me the solution.

The third Question answers my query.

https://vpp.itunes.apple.com/faq

3. Can I distribute redemption codes to employees who are not located in my country?

No. Apps can only be distributed to employees with Apple IDs located in the same country where the apps were purchased. To distribute redemption codes in other countries, you must enroll your business in the Volume Purchase Program for every eligible country in which you wish to purchase and distribute apps.