How to hide Google App Script function in Google Sheet?

In the Google app script project, I created one function for getting a token. It's working fine perfectly in the project. but I noticed that my functions are visible in Google Sheets. And it's returning the token in the Google sheet cell. I had attached the image for that.

--> You can see that I had defined the getTokenFromMacro function for getting token.

--> Here you can see that my functions are visible in the google sheet cell.

So how can I hide my token not to visible to others or how can I hide my function to not to be visible in Google Sheets function?

I used my getTokenFromMacro in a javascript.html file.

Is there any solution to this problem?

Google Apps Script allows you to specify if the function is private or if it will be accessible via Google Sheets:

>The name of a custom function cannot end with an underscore (_), which denotes a private function in Apps Script.

You can change your function declaration to:

function getTokenFromMacro_() {
  const scriptProperties = PropertiesService.getScriptProperties();
  const token = scriptProperties.getProperty('API_TOKEN')
  return token;
}

The error Unknown function: 'getTokenFromMacro_'. will appear when trying to use it as a custom function:

Reference:

• Guidelines for custom functions - Naming

Please, try it: from HTML you'll call a public function - nameYouWant() - and that fucntion will call a private function - getTokenFromMacro_()

in GAS

function nameYouWant(){
 return getTokenFromMacro_()
}

in HTML

google.script.run
 .withFailure...
 .withSuccess...
 .withUser...
 .nameYouWant()