Murad is being supported by Greater London UNISON Labour Link (and he is a former member of my UNISON branch) and a wide range of other affiliates and leading Labour movement figures. In fact, I don't think I have seen such a spread of support in any recent internal Labour election. Have a look at all his endorsements.
All London Labour Party members (128,000 of us I believe) should have got an email from CES firstname.lastname@example.org last week. I got mine on 5/2/20 at 14.12. Check your junk folders but if you did not receive anything contact email@example.com.
It took me about 3 minutes to vote (and if you can find that email you don't need to know your ballot numbers or stuff like that. Click on link in email and you go straight to the vote)
Ballot finishes on 12 noon on Wednesday 19 February 2020.