Remove Mininimize button

i created a package that requires a reboot by adding the follwing:
If (($mainExitCode -eq 0) -OR ($mainExitCode -eq 3010)) {
Show-InstallationRestartPrompt -NoCountdown

When the package completes installation I get 2 buttons, Minimize and Restart Now. I have searched for $ButtonMinize in AppDeployToolkitMain but cannot find any references for this button. I can see all the other buttons including Restart now. How do I remove the minimize button

Open the main script, look for line:


and remove it.