Access Issue with SSO

[spy16x]

I have this following code with v2 SDK:

package main

import (
	"context"
	"fmt"
	"os"

	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/service/ec2"
)

func main() {
	cfg, err := config.LoadDefaultConfig(
		context.TODO(),
		config.WithRegion("ap-south-1"),
	)
	if err != nil {
		fmt.Println("error:", err)
		os.Exit(1)
	}

	fmt.Println(cfg)

	client := ec2.NewFromConfig(cfg)

	identity, err := client.DescribeInstances(
		context.TODO(),
		&ec2.DescribeInstancesInput{},
	)
	if err != nil {
		fmt.Println("error:", err)
		os.Exit(1)
	}

	fmt.Println(identity)
}

And i have 4 profiles configured (works with aws CLI). In the credentials file, 3 of the profiles have aws_access_key_id and aws_secret_access_key configured. For the one production profile, i have the SSO configured and logged in. But when running this code with AWS_PROFILE=prod (the sso profile), i get the following error:

error: operation error EC2: DescribeInstances, https response error StatusCode: 401, RequestID: fe078f76-fc08-4312-a133-d1bb106b9cc6, api error AuthFailure: AWS was not able to validate the provided access credentials