当我用用户名和密码字段在Postman上测试我的登录功能时，它总是得到错误消息“无效凭据”。
我试过修改$credentials变量定义，并搜索论坛，没有任何效果。我没有修改任何原始文件从tymon/jwt-auth，任何东西像改变电子邮件到用户名。对于JWT的版本，我使用tymon/jwt-auth：“dev-develop”。
这是我的用户控制器. php

public function login(Request $request)
    {
        // I changed variable definition from $request->only('email', 'password') to $request->only('username', 'password')
        $credentials = $request->only('username', 'password');

        // variable below have the same results
        // $credentials = ['username' => $request->input('username'), 'password' => $request->input('password')];

        try {
            if(! $token = JWTAuth::attempt($credentials)) {
                // Keep getting this error
                return response()->json(['error' => 'invalid credentials'], 400);
            }
        }
        catch (JWTException $e) {
            return response()->json(['error' => 'could not create token'], 500);
        }

        return  $this->createNewToken($token);
    }

这是我的模型User.php

class User extends Model
{
    use HasFactory;
    protected $table='users';
    protected $primaryKey='id_user';
    public $timestamps=false;
    /**
     * fillable
     * 
     * @var array
     */
    protected $fillable = [
        'nama_user', 'role', 'username', 'password'
    ];
    /**
     * The attributes that should be hidden for serialization.
     *
     * @var array<int, string>
     */
    protected $hidden = [
        'password',
        'remember_token',
    ];

    public function getJWTIdentifier()
    {
        return $this->getKey();
    }
    public function getJWTCustomClaims()
    {
        return [];
    }