Hi, thanks for posting your question!
By default, the learning modules will take the language set on the M365 account. Similar question has previously been answered by a community member. Check out: https://techcommunity.microsoft.com/t5/microsoft-defender-for-office/how-to-change-the-language-for-an-end-user-elearning-module-in/m-p/4167014
Hope this helps!