Huawei cloud provider not work specific iam endpoint

Simple the code example

terraform {
  required_providers {
    huaweicloud = {
      source = "huaweicloud/huaweicloud"
      version = "1.21.0"
   }
}
}


provider "huaweicloud" {
  region      = "cn-north-3"
  access_key  = "*****"
  secret_key  = "*****"

  endpoints = {
    iam = "https://iam.cn-north-3.huawei.com"
    vpc = "https://vpc.cn-north-3.huawei.com"
  }
}

# Create a VPC
resource "huaweicloud_vpc" "example" {
  name = "my_terraform_vpc"
  cidr = "192.168.0.0/16"
}

on start up I get an error:
Error: Authentication failed

on main.tf line 11, in provider “huaweicloud”:
11: provider “huaweicloud” {

In the log I see:
huaweiCloud Request URL: GET https://iam.myhuaweicloud.com:443/v3/projects?name=cn-north-3

why the request doesn’t go to “https://iam.cn-north-3.huawei.com” ?