EC2 metadata service API returns 401 unauthorized error

Hi AWS, I am trying to print the IP address of an EC2 instance using a PowerShell script. I am using an IAM user for the same. These are the set of policies attached to my user:

• AmazonEC2ReadOnlyAccess
• AmazonEC2FullAccess

Original code is:

  $privateIp = $null
  $publicIp = $null
  if ($privateIp -eq $null) {
    try {
        $privateIp = Invoke-RestMethod -Uri "http://169.254.169.254/latest/meta-data/local-ipv4" -ErrorAction Stop
        echo "The deploy job server IP (private) is $privateIp"
    } catch {
        echo "Unable to retrieve private IP address."
    }
  } elseif ($publicIp -eq $null) {
      try {
          $publicIp = Invoke-RestMethod -Uri "http://169.254.169.254/latest/meta-data/public-ipv4" -ErrorAction Stop
          echo "The deploy job server IP (public) is $publicIp"
      } catch {
          echo "Unable to retrieve public IP address."
      }
  } else {
      echo "Unable to retrieve either private or public IP address."
  }

However while running this code it was printing what's written under the catch statement. I tweaked the code to get more insights why this is occurring and the modified code looks like:

          $privateIp = $null
          $publicIp = $null
          if ($privateIp -eq $null) {
            try {
                $privateIp = Invoke-RestMethod -Uri "http://169.254.169.254/latest/meta-data/local-ipv4" -ErrorAction Stop
                echo "The deploy job server IP (private) is $privateIp"
            } catch {
                $errorMessage = $_.Exception.Message
                echo "Error: $errorMessage"
            }
          } elseif ($publicIp -eq $null) {
              try {
                  $publicIp = Invoke-RestMethod -Uri "http://169.254.169.254/latest/meta-data/public-ipv4" -ErrorAction Stop
                  echo "The deploy job server IP (public) is $publicIp"
              } catch {
                  $errorMessage = $_.Exception.Message
                  echo "Error: $errorMessage"
              }
          } else {
              $errorMessage = $_.Exception.Message
              echo "Error: $errorMessage"
          }

and it gave this error message Error: The remote server returned an error: (401) Unauthorized.

Is it because I am missing some IAM permissions as I am not using an EC2 Instance Profile rather using an IAM user or is there any bug in the code. Please suggest.