How do I install libwebkitgtk-1.0-0 on Ubuntu 19.04

Based on this, it seems to only be available for up to 18.10. I would suggest to download the .deb file from the PPA here, by expanding version 2.4.11-4 of webkitgtk for Cosmic (18.10), and downloading libwebkitgtk-1.0-0_2.4.11-4.deb for the correct architecture. Then, use sudo dpkg -i libwebkitgtk-1.0-0_2.4.11-4_<your architecture>.deb. You may also need to install dependencies with sudo apt install -f.

Edit: As @fkraiem said, installing 18.04 will also solve your problems, and I personally recommend using the LTS versions unless you really want the latest version.

Install 18.04... – fkraiem

I am not sure this is something stupid to do, but I was running out of options and this solution solved my problem. (please tell me if I did something idiotic).

I created a bionc.list in /etc/apt/sources.list.d in than file I added the following line:

deb http://cz.archive.ubuntu.com/ubuntu bionic main universe

I ran an apt update and then installed libwebkit normally...

I needed to run Vega and this was the only way I figured to do it...

Good news - it worked... I am waiting for the bad news