Modify pre-existing ELB by Terraform

I would like to import the pre-installed ELB which is not made by Terraform. As far as I know, provisioned EC2s (not created by Terraform) are modified with no problems.

Please refer to: https://www.youtube.com/watch?v=Abv3CHS4HTE

All I want to know is to enable provisioned ELB with the Access logs. (* I don't want to provision a new ELB)

Following is the code I run.

    data "aws_elb_service_account" "main" {}
    
    resource "aws_s3_bucket" "elb_logs" {
      bucket = "<BucketName>"
      acl    = "private"
    
      policy = <<POLICY
    {
      "Id": "Policy",
      "Version": "2012-10-17",
      "Statement": [
        {
          "Action": [
            "s3:PutObject"
          ],
          "Effect": "Allow",
          "Resource": "arn:aws:s3:::<BucketName>/AWSLogs/*",
          "Principal": {
            "AWS": [
              "${data.aws_elb_service_account.main.arn}"
            ]
          }
        }
      ]
    }
    POLICY
    }
    
    resource "aws_lb" "foobar" {
      arn                = "arn:aws:elasticloadbalancing:ap-northeast-1:<AccountName>:loadbalancer/app/<ELBName>/7c6a359c72a9a02e"
      name               = "<ELBName>"
      internal           = false
      load_balancer_type = "application"
        subnets                    = [
            "<Subnet-1Name>",
            "<Subnet-2Name>",
        ]
      access_logs {
        bucket   = "${aws_s3_bucket.elb_logs.bucket}"
      }
    }

You need to import the existing load balancer into the terraform state:

$ terraform import aws_lb.foobar LB_ARN

(replace LB_ARN with the ARN of the load balancer).