I have a website https://www.monitup.com/ for the system to work, customers need to download the msi setup file written in C # and turned into an installation project.

There is no problem so far, the point where I am stuck is that I cannot understand which customer has installed and used the application. During the download I have to embed the customer number in the msi file. I also need to read this customer number during setup.
Now, during the installation phase, I want the customer to enter their number as follows.

However, this method does not work when users want to install remotely on other computers with a tool like Psexec. I need to auto detect customer number during setup. I did not know how to call this, I have a hard time explaining it because I don't know the name.