[Fechado] I'm trying to translate a button I added manually to the Divi Header on my site link oculto...

Background of the issue:
I am trying to translate a button I added manually to the Divi Header on my site link oculto using WPML. The button text 'Book Demo' is repeated in another button on the main page, and there is a string translation of 'Book Demo' to 'Demo buchen'. The button is not contained in the menu because I created the website with the Divi Builder and couldn't add a button in the menu that is styled differently than the rest of its content.

Symptoms:
The translation doesn't take effect in the header-button. I expected to see 'Book Demo' in the English header and 'Demo buchen' in the German header, but I got 'Book Demo' in both languages.

Questions:
Why is the translation not applied to the header button?
How can I ensure the header button text is translated correctly?