I use the https://clipboardjs.com/ library to copy text to the clipboard.

In all examples, you need to press the button. But how to implement it without a button?

init_clipboard();
copy_to_clipboard ('mytext');

In clipboard.js example:

var clipboard = new Clipboard('.btn', {
    text: function() {
        return 'to be or not to be';
    }
});

with button

<button class="btn">Copy</button>

But I want without a button and user activity