Installing IJulia for all users for JupyterHub

Ok, so I’m attempting to follow the instructions on this post (Julia kernel on JupyterHub system-wide LDAP - #6 by barche) and I’m running

$ JULIA_DEPOT_PATH=/opt/julia-1.4.2/share/julia sudo julia
               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.4.2 (2020-05-23)
 _/ |\__'_|_|_|\__'_|  |  Official https://julialang.org/ release
|__/                   |

(@v1.4) pkg> add IJulia
   Updating registry at `~/.julia/registries/General`
   Updating git-repo `https://github.com/JuliaRegistries/General.git`
  Resolving package versions...
   Updating `~/.julia/environments/v1.4/Project.toml`
 [no changes]
   Updating `~/.julia/environments/v1.4/Manifest.toml`
 [no changes]

It looks like it’s still using the local depot. How do I get it to switch to the global one?