What is the meaning of 'lean all in my bladder'?

Assuming Genus Lyrics' "Verified Artist" icon is correct, the actual author, Lil Nas X, has commentary on this line

ARTIST Lil Nas X 5,977 3 months ago This second verse is where I’m in this better lifestyle. I have me a brand new tractor. I’m on some Lean–not trying to endorse that, by the way. But I’m in a higher place now.

I believe "Lean" is one street name for a recreational drink using prescription strength cough syrup that contains codeine.

The drug Promethazine with Codeine is commonly known "on the street" as "syrup" and/or "lean," the latter due to the abusers’ propensity of having difficulty in standing up straight.