![Swagger UI](https://fastapi.tiangolo.com/img/index/index-03-swagger-02.png)

* Click on the button "Try it out", it allows you to fill the parameters and directly interact with the API:

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-04-swagger-03.png)

* Then click on the "Execute" button, the user interface will communicate with your API, send the parameters, get the results and show them on the screen:

## Es in Aktion sehen

Öffnen Sie die interaktive Dokumentation: <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

### Authentifizieren

Klicken Sie auf den Button „Authorize“.

Verwenden Sie die Anmeldedaten:

Benutzer: `johndoe`

Passwort: `secret`.

<img src="/img/tutorial/security/image04.png">

Nach der Authentifizierung im System sehen Sie Folgendes:

## See it in action

Open the interactive docs: <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

### Authenticate

Click the "Authorize" button.

Use the credentials:

User: `johndoe`

Password: `secret`

<img src="/img/tutorial/security/image04.png">

After authenticating in the system, you will see it like:

.screenshot:before {
  content: '';
  position: absolute;
  top: 15px;
  left: 15px;
  display: inline-block;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  /* A little hack to display the window buttons in one pseudo element. */
  background: #d9515d;
  -webkit-box-shadow: 25px 0 0 #f4c025, 50px 0 0 #3ec930;
          box-shadow: 25px 0 0 #f4c025, 50px 0 0 #3ec930;

* 🔧 Correct DeprecationWarning config and comment in pytest settings. PR [#4008](https://github.com/tiangolo/fastapi/pull/4008) by [@graingert](https://github.com/graingert).
* 🔧 Swap light/dark theme button icon. PR [#3246](https://github.com/tiangolo/fastapi/pull/3246) by [@eddsalkield](https://github.com/eddsalkield).

Go to the *path operation* "Get `/slowusers/`" in all of the tabs. Use the "Try it out" button and execute the request in each tab, one right after the other.

The tabs will wait for a bit and then some of them will show `Internal Server Error`.

### What happens

    content: '';
    position: absolute;
    top: 15px;
    left: 15px;
    display: inline-block;
    width: 15px;
    height: 15px;
    border-radius: 50%;
    /* A little hack to display the window buttons in one pseudo element. */
    background: #d9515d;
    -webkit-box-shadow: 25px 0 0 #f4c025, 50px 0 0 #3ec930;
            box-shadow: 25px 0 0 #f4c025, 50px 0 0 #3ec930;
}

[data-termynal]:after {

                """
                The OAuth2 redirect endpoint for the Swagger UI.

                By default it is `/docs/oauth2-redirect`.

                This is only used if you use OAuth2 (with the "Authorize" button)
                with Swagger UI.
                """
            ),
        ] = "/docs/oauth2-redirect",
        swagger_ui_init_oauth: Annotated[
            Optional[Dict[str, Any]],
            Doc(

  - author: Amit Chaudhary
    author_link: https://twitter.com/amitness
    link: https://amitness.com/2020/06/fastapi-vs-flask/
    title: FastAPI for Flask Users
  - author: Louis Guitton
    author_link: https://twitter.com/louis_guitton
    link: https://guitton.co/posts/fastapi-monitoring/
    title: How to monitor your FastAPI service
  - author: Precious Ndubueze
    author_link: https://medium.com/@gabbyprecious2000