Error Inappropriate value for attribute "user": string required

Terraform
1

Hello everyone
I have an error
Inappropriate value for attribute “user”: string required

I want to make multiply ssh connection
Like appuser1,appuser2,appuser3
To create all this user’s and make connection to them
My variable is

variable "ssh_keys" {
  type = list(string)
  description = "add ssh keys"
}

My terrafor.tfvars

ssh_keys = [
“appuser:ssh-rsa {ssh key} appuser”,
“appuser1:ssh-rsa {random ssh key} appuser1”,
“appuser2:ssh-rsa {random ssh key}appuser2”,

user = “appuser,appuser1,appuser2,appuser3”

My error

“var.user is a list of string, known only after apply
│
│ Inappropriate value for attribute “user”: string required.”

Plz, be nice