This sounds like a local rights issue on the machine. Likely our IT security doesn't let anyone who isn't a domain admin install things on their own machine.
If you are able to manually make the user domain account a local admin, they would be able to install themselves. Otherwise, someone with admin credentials for that machine will have to enter their credentials to get the program installed.
Yes, the user does not have rights, but the field services tech has admin credentials. He installed it, and when she goes to launch the program in her sign-on she's getting this popup, and the popup requires admin credentials. Do you think if the field services tech entered his credentials to say yes, the program can make changes, that the popup will stop? Is this a one-time popup after installation?
It should only ask once, as it needs Admin rights to finish the process.
However, what it sounds like is that security on the machine is requiring the user to have local rights to run the program. Maybe someone else can elaborate if they've seen the message like that more recently.
Might be Help Desk People can help you on this issue, Usually, it more about Local Administrations issue which can be solved by System Admins.
Better reach help desk and check they might have More Rights.