Isso ocorre porque o **OAuth2** usa "dados de um formulário" para mandar o **username** e **senha**.

Execute esse exemplo com:

<div class="termy">

```console
$ uvicorn main:app --reload

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

## Verifique-o

package cmd

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io/fs"
	"os"
	"sync"

	"github.com/dustin/go-humanize"
	"github.com/minio/minio/internal/color"
	"github.com/minio/minio/internal/config"
	"github.com/minio/minio/internal/config/storageclass"
	xioutil "github.com/minio/minio/internal/ioutil"
	"github.com/minio/minio/internal/logger"

</a>
<a href="https://pypi.org/project/fastapi" target="_blank">
    <img src="https://img.shields.io/pypi/v/fastapi?color=%2334D058&label=pypi%20package" alt="Package version">
</a>
<a href="https://pypi.org/project/fastapi" target="_blank">
    <img src="https://img.shields.io/pypi/pyversions/fastapi.svg?color=%2334D058" alt="Supported Python versions">
</a>
</p>

---

</a>
<a href="https://pypi.org/project/fastapi" target="_blank">
    <img src="https://img.shields.io/pypi/v/fastapi?color=%2334D058&label=pypi%20package" alt="Package version">
</a>
<a href="https://pypi.org/project/fastapi" target="_blank">
    <img src="https://img.shields.io/pypi/pyversions/fastapi.svg?color=%2334D058" alt="Supported Python versions">
</a>
</p>

---

</a>
<a href="https://pypi.org/project/fastapi" target="_blank">
    <img src="https://img.shields.io/pypi/v/fastapi?color=%2334D058&label=pypi%20package" alt="Package version">
</a>
<a href="https://pypi.org/project/fastapi" target="_blank">
    <img src="https://img.shields.io/pypi/pyversions/fastapi.svg?color=%2334D058" alt="Supported Python versions">
</a>
</p>

---

   * The HTTP <a
   * href="https://wicg.github.io/user-preference-media-features-headers/#sec-ch-prefers-color-scheme">{@code
   * Sec-CH-Prefers-Color-Scheme}</a> header field name.
   *
   * <p>This header is experimental.
   *
   * @since 31.0
   */
  public static final String SEC_CH_PREFERS_COLOR_SCHEME = "Sec-CH-Prefers-Color-Scheme";

  /**
   * The HTTP <a

            zos.closeEntry();

            // Add CSS file
            ZipEntry cssEntry = new ZipEntry("css/style.css");
            zos.putNextEntry(cssEntry);
            zos.write("body { color: red; }".getBytes());
            zos.closeEntry();
        }
    }

    private void createMockThemeZipWithSkippedEntries(Path zipPath) throws IOException {

 * </ul>
 *
 * <p>An exception that is suppressed is added to the exception that <i>will</i> be thrown using
 * {@code Throwable.addSuppressed(Throwable)}.
 *
 * @author Colin Decker
 * @since 14.0
 */
// Coffee's for {@link Closer closers} only.
@J2ktIncompatible
@GwtIncompatible
public final class Closer implements Closeable {
  /** Creates a new {@link Closer}. */

```

Esto se debe a que **OAuth2** utiliza "form data" para enviar el `username` y `password`.

///

Ejecuta el ejemplo con:

<div class="termy">

```console
$ fastapi dev main.py

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

## Revisa

</a>
<a href="https://pypi.org/project/fastapi" target="_blank">
    <img src="https://img.shields.io/pypi/v/fastapi?color=%2334D058&label=pypi%20package" alt="Package version">
</a>
<a href="https://pypi.org/project/fastapi" target="_blank">
    <img src="https://img.shields.io/pypi/pyversions/fastapi.svg?color=%2334D058" alt="Supported Python versions">
</a>
</p>

---