What payment systems are available (e-money or cards)?

Question

PHP

Tell me, what services are there for payment or services?
What are their + and - .
How difficult is it to connect?
Security (so that this doesn’t happen: I ordered for 1000 parrots, opened the console, changed the value and paid 1 parrot ...)
Where the money will come is not so important, but I’ll ask your opinion .. where is it best to send them and how to check automatically what they came?
Example: the user ordered 2 services for the amount of 2000 parrots. Paid only 1900 parrots.
Maybe someone saw in the admin panels of stores such garbage as the status of payment...
Order No. | ordered for | paid
1 | 2000 | no (red)
2 | 2000 | 2000 (green)
3 | 3200 | 3000 (yellow)
Here is an example..

Answer 1

Here are a couple of security testing services for you .. if the application is not pierced, then the services will be to blame for errors, not you.
And he wants something like, 1 for a link to pay and then by itself .. and the answer can be decided by the answer.

Answer 2

Each payment system has its own interface. You need to contact their customer service of the particular bank where you have an agreement and an account. They also provide for a certain time the opportunity to test the interface with fake data.

Answer 3

You can use ready-made payment systems (for example: Robokassa) or use the payment systems API and do it yourself.
Many payment systems require a personal WebMoney passport.
Payments are accepted by sending a GET / POST request to the system server with certain data. The server gives you the result of the signature (most likely, you will have to generate it again), which is generated from the characteristics you provided to the payment system server. (For example: password + unique key + amount + product number + user ID, all in md5 format)
After the response from the payment system server is received, you encrypt your data according to the same principle that encrypts the payment system server. By comparing these data, you make a conclusion about the correctness of the payment.

Answer 4

This issue is usually solved by any aggregator of payment systems, they usually screen the process of payment and return of the result perfectly, and it is difficult to hack it, choose for yourself purely on the basis of% of the system and type of activity.
There is a comparison here www.seomagia.ru/article/money/payment-aggregators.html though I can’t vouch for the accuracy of the data
+ it’s very easy to embed into the site