Ecs-tasks.amazonaws.com

 resource "aws_iam_role" "ecs_task_role" {
 name               = "your-ecs-task-role"
 assume_role_policy = <<-EOF
 {
   "Version": "2012-10-17",
   "Statement": [
     {
       "Sid": "",
       "Effect": "Allow",
       "Principal": {
         "Service": "ecs-tasks.amazonaws.com"
       },
       "Action": [
         "sts:AssumeRole"
       ]
     }
   ]
 }
 EOF
}

ECS execution policy

AWS IAM role, AWS service roles, AWS IAM Roles Anywhere: [ list-roles | get-role | create-role | put-role-policy | create-service-linked-role | attach-role-policy | update-role | add-role-to-instance-profile ], aws ec2 describe-iam-instance-profile-associations ], IAM roles for EC2 instances, AWSServiceRoleForAutoScaling