Your second steps installation file not found is weird, trust me I tested several servers including EC2, Linode, checked it’s codebase but didn’t found anything. Everything is functional.
It will be great if you try it to another VPS or try it to a cPanel powered server, you can just make a try.
Else please read the manual installation docs https://www.themeqx.com/docs/teachify-lms/getting-started/installation/
We will be happy if you can use it.