need colon

init.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"os"
+	"strings"
 
 	"github.com/TerribleDev/fiber-test/people"
 	"github.com/gofiber/fiber/v2"
@@ -21,6 +22,9 @@ func main() {
 	if port == "" {
 		port = ":3000"
 	}
+	if !strings.HasPrefix(port, ":") {
+		port = ":" + port
+	}
 
 	app.Listen(port)
 }