JavaScript error: on button element, click is not a function?

I’m having issues with JavaScript not detecting the click event on a button. Here is my HTML code:

<input type="button" value="Upload" id="filemanagement_uploadbutton[0]" name="filemanagement_uploadbutton" onclick="javascript:uploadFiles();">

Here is my JavaScript code (with console.log commands for error checking):

let fileButtons = document.getElementsByName('filemanagement_uploadbutton');
console.log(fileButtons.length);          //returns 2, since I have two buttons
console.log(fileButtons[0].id);           //returns filemanagement_uploadbutton[0]
console.log(fileButtons[0].type);         //returns button
console.log(fileButtons[0].click);        //returns javascript:uploadFiles();
fileButtons[0].click();

I’ve also tried:

let fileButton = document.getElementsByName('filemanagement_uploadbutton')[0];
fileButton.click();

Both of these result in the error:

Uncaught TypeError: fileButtons[0].click is not a function

or

Uncaught TypeError: fileButton.click is not a function

How is it telling me that click is not a function on the element that it’s telling me the click function is “javascript:uploadFiles();” literally one element above?

Any insights? Thanks!