The file is required because JuliaPro uses an authenticated package server, pkg.juliahub.com (maintained by Julia Computing, like JuliaPro itself). This server supports integration with https://JuliaHub.com which requires knowing who you are (for example, imminently forthcoming ability to send compute from you JuliaPro to the cloud, with parallelization). For that it needs an
auth.toml file. JuliaPro should be generating that file for you automatically and saving it to the right place.
In order to authenticate you, there is a flow where you need to visit a web page on https://JuliaHub.com in your browser to prove that you are who you say you are. It is possible that is not happening for some reason—maybe JuliaPro does not have a way to open a browser window for you, or the window is being suppressed when it does. Saving that file yourself is not normal and indicates that something is wrong with the normal auth flow on your system. More detail about what does and doesn’t happen and about your system would be helpful to figure out what is going wrong. If you’re comfortable providing it here, that’s good, otherwise you can send DMs to me and I will make sure the JuliaPro/Hub team gets them.