It used to be that you couldn’t get a new custom youtube URL. Now you can.
Here is what youtube says,
“You can’t change a custom URL after creation. However, you can remove the custom URL from your channel and claim a new one if you want to change it. Note that once you remove a custom URL it may become free to be claimed by another creator. In general, a YouTube channel may only have one (1) custom URL and custom URLs cannot be transferred or assigned to anyone.”
