Hey, Terje!
Jason here from Shopify Support. Thank you for reaching out!
You can change the language of the dynamic checkout button by changing your theme’s language. For instance, when I switch the theme’s language to French, the dynamic checkout button also switches to French.
As long as your theme supports the language, you can switch the theme’s language by Shopify admin > Online Store > Themes > Actions > Edit Languages. Just right below the heading, click on Change theme language.
A popup window will show you which language is available on the theme. Keep in mind that in order to switch language, the theme has to be published first.
Please note: If you have the theme’s language set in French and the customer has an English browser, it’s still going to be showing in French. The button isn’t responsive to the browser’s language.
I hope this information helps, however, should you have any questions, please don’t hesitate to reply back here and I’d be happy to help out!
All the best,
Jason