After installation: add to cart does not work, brakes the elementor page

Hello, as in description:

1. fresh install no upsells added yet,
2. i activate the plugin
3. i go to product page and it does not show the upsell popup after click ADD to CART
4. popup does not show, no console errors recorded
5. the page desctiption is in elementor and it is broken, code does not load properly
6. i disable the plugin on plugins page -> all works normally

I will not attach screenshots because it`s a LIVE site, and I switcvhed the plugin off.