You tried going to https://neuroscience.ubc.ca/2020/06/22/adult-born-neurons-develop-longer-previously-thought-and-are-distinct-neonatally, and it doesn't exist. All is not lost! You can search for what you're looking for.
https://neuroscience.ubc.ca/2020/06/22/adult-born-neurons-develop-longer-previously-thought-and-are-distinct-neonatally