i keep getting cors problem

[Dancingaroundthelies]

so i have a project that use both nextjs and golang as its frontend and backend. I keep getting blocked from fetching my data because of CORS

this is my cors code on the backend :

import (
	"net/http"

	"github.com/gin-gonic/gin"
)

func CORSMiddleware() gin.HandlerFunc {
	return func(c *gin.Context) {

		c.Header("Access-Control-Allow-Origin", "http://localhost:5051")
		c.Header("Access-Control-Allow-Credentials", "true")
		c.Header("Access-Control-Allow-Headers", "Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization, accept, origin, Cache-Control, X-Requested-With")
		c.Header("Access-Control-Allow-Methods", "POST, HEAD, PATCH, OPTIONS, GET, PUT, DELETE")

		if c.Request.Method == http.MethodOptions {
			c.AbortWithStatus(204)
			return
		}

		c.Next()
	}
}

i already specify the origin to my localhost domain but it wont work and i also have experimented in my frontend code to put no-cors but still no result. Please help me out