On ubuntu 19.04, libssl1.0.0 is no longer on the repositories. This means that sudo apt-get install libssl1.0.0 does not work. In order for the launcher to run I had to download and install the deb package files (for 64 bit and 32 bit) manually from the previous ubuntu version repositories, which is an advanced task.
I hope our brave devs read this, and who knows, decide to migrate the launcher to libssl1.1 
For those who encounter the problem, the required files can be downloaded and installed like this from the terminal:
wget http://archive.ubuntu.com/ubuntu/pool/main/o/openssl1.0/libssl1.0.0_1.0.2n-1ubuntu6.2_amd64.deb
wget http://archive.ubuntu.com/ubuntu/pool/main/o/openssl1.0/libssl1.0.0_1.0.2n-1ubuntu6.2_i386.deb
sudo dpkg -i ./libssl*.deb