authMiddleware, err := jwt.New(&jwt.GinJWTMiddleware{
		Realm:       "Dragonfly",
		Key:         []byte("Secret Key"),
		Timeout:     2 * 24 * time.Hour,
		MaxRefresh:  2 * 24 * time.Hour,
		IdentityKey: identityKey,

		IdentityHandler: func(c *gin.Context) any {
			claims := jwt.ExtractClaims(c)

			id, ok := claims[identityKey]
			if !ok {
				c.JSON(http.StatusUnauthorized, gin.H{
					"message": "Unavailable token: require user id",
				})
				c.Abort()
				return nil
			}

			c.Set("id", id)
			return id
		})

package main

import (
	"errors"
	"fmt"
	"time"

	"github.com/golang-jwt/jwt/v4"
)

func (stc *DragonflyTokenClaims) Valid() error {
	// Verify expiry.
	if stc.ExpiresAt <= time.Now().UTC().Unix() {
		vErr := new(jwt.ValidationError)
		vErr.Inner = errors.New("Token is expired")
		vErr.Errors |= jwt.ValidationErrorExpired
		return vErr
	}
	return nil
}

type DragonflyTokenClaims struct {
	Id        int32 `json:"id,omitempty"`
	ExpiresAt int64 `json:"exp,omitempty"`
	Issue     int64 `json:"orig_iat,omitempty"`
}

func main() {
	signingKey := "Secret Key"
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, &DragonflyTokenClaims{
		ExpiresAt: time.Now().Add(time.Hour).Unix(),
		Id:        1,
		Issue:     time.Now().Unix(),
	})
	signedToken, _ := token.SignedString([]byte(signingKey))
	fmt.Println(signedToken)
}