Issues with Julia: package not properly installed

I am trying to install this tool in Julia https://github.com/wangjie212/TSSOS. I am a complete beginner with Julia. What is the issue?

After installing TSSOS using the Julia package manager I want to work with it. Once I use

using TSSOS

I obtain the following message:

For some reason the dependency Mosek is not properly installed. I do follow the instructions

using Pkg
Pkg.build("Mosek")

and I get the message that nothing changes. I also tried

Pkg.add("Mosek")

and I get the same message. Basically this dependency is already installed.

Any ideas why I cannot actually use TSSOS?

I am on macOS with Julia 1.5.1 and this is working for me (which I know is not helpful but a good indication this package ~should~ work). My guess is that you have previously done work with Mosek outside of your Julia env? (See here: https://github.com/MOSEK/Mosek.jl#note-on-versions-and-release for why this would potentially make a difference) If that is the case, See here: https://github.com/MOSEK/Mosek.jl#installation for details on ensuring you have a clean install of Mosek downloaded on your device.

It may also be worth testing things like using Mosek to see the error it gives and then doing a ] resolve and ] update in the package manager to ensure any version issues are taken care of. If this yields any new results, please update your question above with that info.