Dynamic Links for our WordPress Site

We at Majority Radios are in the process of building a new website for the business using Wordpress. There are two core functions we want to achieve with our website which is to direct people to our Amazon and eBay stores and get existing customers to register their products and review them on Amazon and eBay. How we want to achieve this is with a page for each product in our range that has links at the top to Amazon, eBay and our sister website iZilla where the item is available for purchase and a registration form at the bottom that generates a popup on submission that is populated with links to the respective product’s review page on Amazon and eBay. Obviously, each product page on Amazon, eBay and iZilla has its own unique URL as does the review pages. What we need is to be able to dynamically generate these URLs using information provided within each product page on our website. What we have so far on the backend of each product page are a series of Advanced Custom Fields for each online marketplace (Amazon UK, Amazon EU, eBay and iZilla). In those fields, I have been inputting the products unique identifier for each website (Amazon ASIN, eBay ID). These identifiers are found on every single product on Amazon and eBay and can be located in the URL. For example: [login to view URL] this is a standard Amazon product link; the series of numbers and letters is called an ASIN and is the unique identifier for a particular item. www.amazon.co.uk/review/create-review/ref=cm_cr_dp_wrt_top/?asins=B07GYRVP61 this is a standard Amazon review link; just like the product link, it too has the ASIN on the end of the URL. The same numbering and linking system is used for eBay products as well. What we want to achieve is a way of inputting these unique numbers into the advanced custom field on the backend of every product page and then every product or review link pulls this information and places it at the end of a predefined URL. What would be ideal is there were some way of creating tags for each custom field that can be added to the end of a URL (e.g. permalinks in WordPress use % tags to define dates, categories, author etc. at the end of a page link). An example of this would be: [login to view URL]%ASIN% This way; when the link is clicked, the %ASIN% in the link will be replaced with the ASIN number localised on the backend of each product page. It would be advantageous if this could be added to the settings in ACF where we can define the tag ourselves, much like creating a custom slug for post categories. This would be our preferred method of solving the issue, but we are open to suggestions on how best to achieve this functionality. Th last part of our requirements is that we have to generate two separate product and review links for UK and for EU versions of each product on Amazon. This is because the UK models and EU models are classed as two different products and therefor do not have the same ASIN. What we want to achieve is the ability for our European customers to click a link to either the Amazon product page or review page and it to be able to direct them to the correct Amazon store depending on the country they are from (German customers to German Amazon etc). This has to be separate from the UK versions. If you require further information or if there is anything I haven’t outline proficiently, do not hesitate to ask and I can discussing everything in more details. The plugins we are using at the moment are: • Advanced Custom Fields • Popup Maker • Ninja Forms