There’s a Debian package available for Citrix Receiver, so in principle this task should be trivial.
It’s not.
Simply installing the package leaves you with a SSL error whenever you try to connect to a Citrix resource. You need to jump through a couple of extra hoops to get it actually working.
Installing the Package
Download the package from here (scroll down to the “Debian Packages” section).
Install it.
sudo dpkg -i icaclient_13.10.0.20_amd64.deb
Now you need to sort out the SSL certificates.
Sorting the Certificates
Link in the certificates (these should already be resident somewhere on your machine).
sudo ln -s /usr/share/ca-certificates/mozilla/* /opt/Citrix/ICAClient/keystore/cacerts/
Create a hash for each certificate.
sudo c_rehash /opt/Citrix/ICAClient/keystore/cacerts/
And you are ready to roll! Connect to your Citrix resources. Enjoy.
Update
The latest package is available from https://www.citrix.com/downloads/workspace-app/linux/workspace-app-for-linux-latest.html. Download the latest .deb file and then install.
dpkg --purge icaclient
dpkg -i icaclient_20.04.0.21_amd64.deb