Use the language option, available in the Profile>Language (your profile image in the upper right corner), to change the language settings and view the web client in any of the supported languages.
The selected language will be used for texts on all pages, options, dialog boxes, status messages, etc. The language settings apply per user and the default language is English.
Read about Desktop Client language settings here.
You can join our community of multilingual users of products and contribute translations for future versions of the software.