The specific project is an application that restricts each user in terms of what they can do. To try it out, you create a user and then create some records that only you can delete and modify.
Such systems are widely used wherever there are many users and aim to ensure that no one will tamper with something that does not belong to them.

The said work is a product of a course from the educational platform Udemy with instructor Michael Spinks.
Excellent instructor and colleague, and essentially from him I learned how to create applications that control and ensure that each user has specific capabilities.

Since I haven't added a mechanism for you to delete the user you will create, I have created two users for you to experiment freely within the application to see its capabilities and to see that each has their own space in the system. Therefore, any action you take with one cannot affect the other.

User 1
Username: daramas
password: 123

User 2
Username: kakanos
password: 1234567

Also, you can attempt to log in with incorrect user credentials to see the result..
If you create your own user, there's no issue, I will simply delete them manually periodically. But feel free to try and this mechanism as well.

Technical details:
In the aforementioned project, PHP and MySQL are used (I built the front-end for the demo).
It relies on temporary token generation.
I liked his approach both in terms of SQL injections and in reducing DOS attacks.
In general, it is a very good project that I recommend even to colleagues who are looking into how to implement custom authentication systems (despite the many frameworks and CMS, it is good to know how to do such things).
*Any interested colleague can find the course on Udemy titled 'Create a REST API using basic PHP with Token Authentication.