What's the best timing to start?

I'm currently breastfeeding my 15 month old (although I'd like to stop), and I'd also like to have a second baby by the time he's 3yo. I've decided I want to start Mounjaro and that decision really has made me hopeful after many years of struggling with my weight,self image, binging disorder, and food noise. So on one hand I don't want to wait any longer, on the other I'm uncertain due to the situation. Do I start after I've stopped breastfeeding and until I get pregnant, or do I wait after I've given birth to baby #2? I'd appreciate any advice!