I see a couple of different issues with this current code. Let's start at the main issue, which is that you're only seeing the last item in the list of leads. I'm going to assume that you understand where in general the issue might be. But if not, take a moment to ponder where it might be (spoiler: ||the renderLeads() function||).
Then take a closer look at that code. You have three distinct sections: 1) some stuff you do once initially, 2) a loop that iterates each of the leads, and 3) some stuff you do once afterwards. Given what you want/expect that code to be doing, ask yourself if the code in each of those sections is in the proper place. Is the code that is executed only once really meant to be done only once? Or should it perhaps be moved elsewhere?