Log in to BRP
Click on your name in the top right corner > Choose language
If you don't have the "choose language" button in BRP:
In this case you need to change the language in your browser.
Log out of BRP
Open Google Chrome
Go to Settings by clicking the three dots in the top right corner
Click on "Language"
Add your language and check "Show Google Chrome in this language"
Restart your browser and log back in to BRP.