Using JavaScript instead of AppleScript to automate a QuickTime Player Audio Recording for a specified time on macOS Catalina.

QuickTime Player Audio Recording.scpt

/* 
JXA JavaScript for Automation
Working in macos Catalina 10.15.1 
Resources:
https://developer.apple.com/library/archive/documentation/LanguagesUtilities/Conceptual/MacAutomationScriptingGuide/index.html#//apple_ref/doc/uid/TP40016239-CH56-SW1

*/

editor = Application.currentApplication(); // Script Editor
editor.includeStandardAdditions = true;

var app = Application('QuickTime Player');
// Need standard additions for UI Scripting
app.includeStandardAdditions = true

console.log("How many minutes would you like to record for?");

var response = editor.displayDialog("How many minutes would you like to record for?", {
    defaultAnswer: "",
    withIcon: "note",
    buttons: ["Cancel", "Continue"],
    defaultButton: "Continue"
})

/* Set variables */
var recordingTimeInMinutes = response.textReturned;
var recordingTimeInSeconds = recordingTimeInMinutes * 60;
/* Examples of date and path variables */
/* You have to use `backticks` for string interpolation to work. Single and double quotes don’t work! */
var dateString = editor.currentDate().toString();
// Not used in this example
var path = Path(`/Users/yourusername/${dateString}.m4a`)

/* Start a QuickTime Player audio recording and stop after delay */
app.activate()
var audioRec = app.newAudioRecording();
audioRec.start();
delay(recordingTimeInSeconds);
app.activate();
audioRec.stop();

/* UI Scripting to bring up save sheet, enter a name, and press return */
events = Application("System Events")
app.activate();
// Wait for QuickTime Player to be on top
delay(1);
events.keystroke(
    "s", 
    {using:"command down"}
);

// Wait for save sheet
delay(2);
/* ` Backticks ` required for string interpolation */
events.keystroke(
    `${dateString}.m4a`
);

delay(2);
/* press return key
https://eastmanreference.com/complete-list-of-applescript-key-codes
*/
events.keyCode(
    36
)