Add a payment gateway to the site

We need to connect a cash register system (PRRO) to an online store on the OpenCart 2.3.x platform. The specific one is not critical, but there is an account in Checkbox with a registered Trading Point, cash register, etc. We are using a simple CRM https://api.net.ua/. There are instructions for integration with Checkbox: https://api.net.ua/%d0%bf%d1%80%d0%be%d0%b3%d1%80%d0%b0%d0%bc%d0%bc%d0%bd%d1%8b%d0%b9-%d1%80%d1%80%d0%be-%d1%81heckbox-ua/ We use 3 types of payments: 1) online via LiqPay 2) transfer to the FOP account (as far as I understand, it does not require fiscalization) 3) cash on delivery via Nova Poshta Please write which PRRO you suggest for integration and the cost.

Hello! I need a specialist in OpenCart for auditing and refining the online store https://www.mineralsspa.com.ua. The situation is as follows: advertising on Meta is working, but there is a problem with conversion. According to Meta statistics, 26 users started the checkout process, but only 2 orders were actually received. Required: check for any technical errors on the site; analyze the cart and checkout process; verify the correct operation of Meta Pixel and events; suggest changes that will help increase conversion; make necessary refinements if needed. Please write: what experience you have with OpenCart; whether you have completed similar tasks; examples of websites you have optimized; an approximate cost for the audit and refinements; when you can start. Thank you!

I need to create a panel Like this: https://upvote.net/ https://upvote.biz/ https://www.buyupvotes.io/ In the future, the possibility of SEO Here is the UpVotes service for Reddit I will have a slightly different service Orders will be fulfilled manually The payment system needs to be connected to Stripe (I have an account) cryptocurrency I am waiting for proposals and timelines

Setting up and testing the payment system for customer payments on the active website. Experience is required! Standard installation and testing (payment by bank card, Apple Pay, etc.). Everything is ready for a quick installation: a working website, a legal entity, bank accounts, two suitable systems selected/downloaded (the work for the specialist will take 1-2 hours). P. S. Experience in website creation is welcome; there will be an additional order for editing the website design and a copy of the website on another domain (the domain has been purchased), setting up another payment system.