Interactive Avatar - set default language in e.g. german

Hello dear friends,
I am currently creating an interactive avatar for a client here in Germany. It would be a great help for the client – and ultimately a significant advantage for you as the provider – if the default language of the avatar could be defined in advance. Ideally, in our case, it should be possible to set German as the default.
Is that possible? And if so, how can it be implemented?
Many thanks in advance!
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