Ryse selects it's language based on the language of the operating system you are running.
Unfortunately, there is no way in the game to change this selection.
You could temporarily switch the language on your operating system. Instructions on how to do this can be found here: https://www.howtogeek.com/232659/how-to-change-the-display-language-in-windows-10/
Ryse will then use this language choice when determining what language to start the game in.
NOTE: Take care if you do this, as you will want to switch languages back afterwards.