Ubuntu – Package ‘libwxgtk3.0-dev’ has no installation candidate on Ubuntu 20.04

Trying to setup a development environment for opencpn on Ubuntu 20.04 (focal).

I get the following error message:

dave@nuc3:~$ sudo apt-get install build-essential cmake gettext git-core gpsd gpsd-clients libgps-dev wx-common libwxgtk3.0-dev libglu1-mesa-dev libgtk2.0-dev wx3.0-headers libbz2-dev libtinyxml-dev libportaudio2 portaudio19-dev libcurl4-openssl-dev libexpat1-dev libcairo2-dev libarchive-dev liblzma-dev libexif-dev libelf-dev libsqlite3-dev
[sudo] password for dave: 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Note, selecting 'git' instead of 'git-core'
Package libwxgtk3.0-dev is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'libwxgtk3.0-dev' has no installation candidate

Can anyone suggest how I might resolve the missing libwxgtk3.0-dev library?