How to correctly use google authenticator when logging in?

Question

PHP

Hello. I need to use google authenticator to provide a more secure login to the site.
The site has 5 users. Here's what I did:
1. Displayed a qr code on a local site, secret key was used to create it, for example "abcd" (just an example)) . I saved this picture to my PC. I also took a picture in the google authenticator program to get a temporary code.
2.In the users table, I created a new field "ga_secret" and set this value to "abcd" for all users.
3. Next, when logging in, I use "ga_secret" to check the introductory code. If everything matches, I enter the site.
4.I have this picture with a qr code. I send it, for example, to emails to all users, they scan it in the google authenticator program and then use the code from the program to enter the site.
Am I understanding the algorithm correctly? Is it correct that ga_secret is the same for all users?
If not, please tell me how it should look like.
Thank you!

Answer 1

Secrets are better to make different for different people. The time zone doesn't matter. The rest is somewhat perverse, but acceptable.

Answer 2

Shared the account - correctly.
But the very fact that you distributed the same authentication data to everyone is a grandiose EPIC FAIL!
You made a HUB, but you need a ROUTER! Do you understand?
Look at the pseudocode and implement a router to have control of each user.
Here is the PHP implementation.