Making edits to a WordPress site

Good afternoon. There is a https://gour-food.com/ site on WordPress with the integration of My Warehouse, Amo CRM, CallTouch. It is necessary to fix some bugs on the site and with existing integrations, as well as integrate the EcommPay payment system (documentation https://developers.ecommpay.com/landing-ru/).

List of fixes:

- Fixing the problem with the fact that the price of the goods is incorrectly displayed from the card to the cart
- Fix the problem with the fact that leads do not come to amo srm
- Output of several grams from MoiSklad of one product to the product card. For example, some positions will have one main weight, some will have 6. If only one weight is added to a particular item in My Warehouse, only that weight should appear on the card.
- Display variations of one weight in the card. Since it is impossible to measure a piece of the same cheese with an accuracy of up to a gram, variations of it are recorded in My Warehouse for each weight. That is, for example, cheese has the option to buy 250 grams. He clicks on 250 grams and opens a list of 6 variations of this weight, for example, 252 grams, 249 grams, etc. He chooses the weight he needs and shows the price specifically for this gram. If a person buys it, then the next one who comes to the card of this product and selects the item 250 grams, he is shown 5 old variations, plus one new one instead of the purchased one (if any).
- If the product ends up in My Warehouse, then it should be hidden on the site. As soon as it is added to My Warehouse, it should appear on the site.
- Separate the texts of the agreements into separate pages (now made crooked popups)
- Add links to the agreement pages, contact information and logo to the footer of the site
- Add a promo code field to the cart and implement the ability to create promo codes in the admin panel
- Connect ecommpay

Please specify the time and cost for this task immediately