osascript needs admin permissions - silhouette studio software

You are not communicating with Apple on these forums, but other regular users such as yourself. If you want to speak with an official from Apple, then you will need to click the "Get Support" link at the top right of this page.

Since you are trying to install software for a plotter I imagine it is trying to install a driver which does require admin permission to install. Even if this is just to install a non-driver helper application, this manufacturer/developer has opted to use a script for the install probably because it needs to install items in multiple locations one of which requires admin privileges and it appears they are using an Apple Script to do so (since you've already spoken with the developers/manufacturer about it). If you want to use this software you will need to provide your admin password or not use their software.

Edit: I should clarify something....confirm with the developer/manufacturer that the OSAScript belongs to the Silhouette software. If the OSA Script is not an official part of the Silhouette software installer, then do not provide your admin password as the script may be some sort of malware.

Did you download the Silouette software from developer's website or from somewhere else? If you downloaded it from the developer's official website, then make sure they know that so they can check their website for issues. If you downloaded the software from somewhere else, then why? Other websites or sources may not be trustworthy and may include other nasties along with the software.

You may want to run MalwareBytes to check that nothing else is on your system.