How to parse a JWT token with RSA in jwt-go ParseWithClaims?

I have developed the following method, which should enable token-based authentication (jwt). An asynchronous process should be used to generate the token.

The source code seems to work up to and including the generation of the signed token.
I encountered an issue when querying the token with ParseWithClaims. Can someone help please?

package controllers

import (
	"crypto/rand"
	rsaKeys "crypto/rsa"
	"fmt"

	jwtgo "github.com/dgrijalva/jwt-go"
	"github.com/gofiber/fiber"
)

func Login(c *fiber.Ctx) error {
	
	type TestClaims struct {
		HAPP string `json:"happ"`
		jwtgo.StandardClaims
	}

	currentPrivateKey, err := rsaKeys.GenerateKey(rand.Reader, 512)

	claims := TestClaims{
		"owa",
		jwtgo.StandardClaims{
			Issuer:    "test",
			ExpiresAt: 15000,
		},
	}

	token := jwtgo.NewWithClaims(jwtgo.SigningMethodRS256, claims)

	tokenSigned, err := token.SignedString(currentPrivateKey)
	if err != nil {
		fmt.Printf("Failed to sign in account %v", err)
	}

	//Issue is in this statement
	_, errTest := jwtgo.ParseWithClaims(tokenSigned, &TestClaims{"owa", jwtgo.StandardClaims{}}, func(token *jwtgo.Token) (interface{}, error) {
		return currentPrivateKey, nil
	})

	if errTest != nil {
		fmt.Printf("Error Message: %v", errTest) //Does throw error: key is of invalid type
	}

	return c.JSON(fiber.Map{
		"message": "success",
	})
}

To validate the JWT you need the public key, specifically ParseWithClaims expects a key of type *rsa.PublicKey.

You can get it from the private key with PrivateKey.Public:

tok, err := jwtgo.ParseWithClaims(tokenSigned, &TestClaims{"owa", jwtgo.StandardClaims{}}, func(token *jwtgo.Token) (interface{}, error) {
    return currentPrivateKey.Public(), nil
})

Please note that dgrijalva/jwt-go is unmaintained. If you can, switch to the community fork golang-jwt/jwt, which includes critical security fixes.