When you use a VPN to connect to the Internet, you use the IP address of one of our encrypted servers instead of your real IP address. As a result, some websites might localize content depending on the server location you are connected to.
For example, if you are connecting to the Japan server, some websites may localize their content and you will see Japanese instead of English text.
As a workaround, try selecting a territory that uses English as its primary language such as locations in the US. To change your server location, follow the steps listed in the How do I choose my server/connection on Mozilla VPN on my desktop or laptop computer? article.