Hi,

We can use the patching method to override a function without changing the source code.

For example, use the below code as a reference:

/** @odoo-module **/

import { patch } from "@web/core/utils/patch";

import { download } from "@web/core/network/download";

import { actionService } from "@web/webclient/actions/action_service";

patch(actionService.prototype, {    async setup() {

        super.setup(); // By using the super function, we can execute all parent functions along with ours.

    },    _triggerDownload(value){        // you can write your logic here    }

});

Please refer to the following blog for better understanding the working of patching, with example:

https://www.cybrosys.com/blog/how-to-patch-existing-owl-component-in-odoo-17

Regards