Hi,

To add more information to corresponding page(products) you have to override the corresponding controller method and pass the necessary information to the template.

For overriding an existing controller see this video: How To Inherit Existing Controller in Odoo

See this example in website_sale_delivery module in which a controller defined in website_sale module is inherited and passing new values ,

from odoo.addons.website_sale.controllers.main import WebsiteSale


class WebsiteSaleDelivery(WebsiteSale):

    @http.route(['/shop/payment'], type='http', auth="public", website=True)
    def payment(self, **post):
        order = request.website.sale_get_order()
        carrier_id = post.get('carrier_id')
        if carrier_id:
            carrier_id = int(carrier_id)
        if order:
            order._check_carrier_quotation(force_carrier_id=carrier_id)
            if carrier_id:
                return request.redirect("/shop/payment")

        return super(WebsiteSaleDelivery, self).payment(**post)

File: https://github.com/odoo/odoo/blob/13.0/addons/website_sale_delivery/controllers/main.py

Thanks