Modifications and add-ons to Codeigniter script

Good evening, We have the tecdiary company script. We want to add some features. Such as: * The script has the option for price list groups. I want the pricing list to have all the brands that the user will add the discount (either in amount or in percent) to a field. When we click update, it will update the product prices for that price list. (The initial product values ​​are in the database in another table.) (TASK - 1) * When importing a client, we want to add the vat search and enter the information automatically. (source of information: [login to view URL]) There is a library on github. It is enough for the software engineer to add the add-on. (TASK - 2 ) For example: The user enters the vat number and presses the check button if there is a result then it will fill in the information in the correct fields. * We have an opencart website. We want product prices to be updated from the database, from our table of initial prices. In the tecdiary script we can similarly adjust the values ​​as in TASK -1 and if he cannot find the product in the database, then let him know by email. (TASK - 3 ) * The system for sale only searches for the code, we want to search with barcode. That is, to look at the barcode column.(TASK - 4) * Software has sale, offer, purchase with separate preference each. We want, at least a dynamic system. That is, the user can create separate prefixes for sale. During the sale you will be able to choose from a document preference. Each prefix will receive a serial number according to its own prefix. Example: Market Sale -> Prefix: MRKSALE-00001 Internet Sale -> Prefix: INT-SALE-00010 (TASK - 5 ) * When selling we want to add a button that will display a search form that the user can search for live by name, barcode, code. In the results whichever product you choose, these will be added to the sales form after confirmation. (TASK - 6 ) * We want to edit the pdf sales document in the software. (TASK - 7 ) * We are also requesting some additions to another script. It is created with codeigniter framework. In our 2 sales pages, we want to add 2 more fields. 1 - Add Total Sales Price with Tax. (There is a field without, we want to add with tax.) 2 - It is possible to discount the price of the product on sale, but on a new tab. We want to add an extra field to the sales table that will refresh the sales price at the discount we will add. (TASK - 8 ) ** I want the freelancer to inform me every 48 hours about the progress of the job. *** Since upgrades to the script are being made at the same time I want the freelancer to write a change-log for convenience.