How to implement a payment system for an opencart store?

Question

Payment systems

Hello experts!
I am a front-end developer, but due to circumstances I have to integrate a payment system plugin into the site, which I have never done.
I need to do the following:

Is it hard to do? I am an amateur in this matter, so I need help with this)

Answer 1

Tell me, you are a front-end developer, how is an SSL certificate self-signed?
What is the difficulty of google translator and translate?
1) Unzip the archive, upload with merging folders to the root of OpenCart
2) From the admin panel go to Admin-users-user groups
3) find and mark unmarked files in both editing and access, save
4) from the admin panel go to Extensions -Payment
5) Install the module and configure by clicking on the Edit button
This is my free translation from the backend developer exclusively to the frontend

Answer 2

It's not hard, here are the instructions:

Answer 3

It's written there step by step.