Our company is using Dynamics 365 portals. All of our content is using the English language. The portal was setup by an external company but I believe it is using the default English language settings.

In the portal languages section of the portal management app the English language code is 'en-US'. I think this code is used to create the 'lang' attribute for the HTML element of the portal website e.g. <html lang="en-US">.

We are a UK company and we would like to use the correct language code 'en-gb' to ensure support for assistive technology users e.g. users with vision impairment may use a screen reader to listen to the site.

When I test the site using a screen reader the site content is announced with an American accent. Do portals support British English language? The following page lists supported languages but only includes 'en-US ' and not 'en-GB':
https://docs.microsoft.com/en-us/power-apps/maker/portals/configure/enable-multiple-language-support

Can I update the existing portal language code from 'en-US' to 'en-GB' and are there any implications to making this change?