r2c/user/plugins/form/app/utils/keep-alive.js

import $ from 'jquery';
import { config } from 'grav-form';

const keepAlive = $('[data-grav-keepalive]');

if (keepAlive.length) {
    const timeout = config.session_timeout / 1.5 * 1000;
    setInterval(() => {
        $.ajax({
            url: `${config.base_url_relative}/task${config.param_sep}keep-alive`
        });
    }, timeout);
}