Unknown root level key: provisioner

I have having issues when using the provisioner file functionality and it is failing with the below error.

Error: Unknown root level key: provisioner

code in my .tf file.

provisioner “file” {
source = “${path.module}/register.sh”
destination = “/tmp/register.sh”

connection {
host = “10.11.9.4”
type = “ssh”
user = “centos”
agent = false
private_key = “{file("{path.module}/id_rsa”)}"
}
}

In variable.tf.

variable “private_key” {
type = “string”
}