Here is the YouTube trailer
Here is the BBC link which is only available in the UK 🇬🇧
https://www.bbc.co.uk/iplayer/episode/b084xk6m/planet-earth-ii-5-grasslands
And the BBC trailer as well
https://www.bbc.co.uk/programmes/p0gqjy5v
It is currently being translated into French 🇫🇷, look out for it in your region!