Unable to use Messenger on my Apple Watch

Here is my problem... I am following these instructions online, but the Apple Watch option is NOT in there as it is pictured below:

Therefore, I am unable to tap on the non-existing Apple Watch cell.

Thanks Julieda - I did that. It is turned on. But whenever I touch the Messenger Icon on my Apple Watch I get a message that says, "Log in from the paired iPhone." When I go to the paired iPhone, I'm already logged in. When I go to the Messenger app as described in this online tutorial, the Apple Watch option is absent in my Messenger App...