The following packages have unmet dependencies:
esl-erlang : Depends: libssl0.9.8 but it is not installable
Depends: libwxbase2.8-0 but it is not installable
Depends: libwxgtk2.8-0 but it is not installable
E: Unable to correct problems, you have held broken packages.
The current instructions point at an old debian erlang package, current erlang docs point to the 2.0:
This results in this error on ubuntu 20.04: