Amazon web services – Using a terraform file (that is not created yet) in terraform file function

I am trying to create a terraform that will create a windows server, linux machine in an aws vpc and then will save the Windows server and the admin password in a local file,

I Know that I will need the keypair in order to decrypt the password of the windows server, though, I am assuming that the indrastructure won’t have a key-pair on their end,

please find my terrform main.tf (as this is the only file for now):

### Creating a Dedicated VPC for the project

module "vpc" {
  source = "terraform-aws-modules/vpc/aws"

  name = "Moc-Winsev"
  cidr = "10.0.0.0/16"

  azs            = ["us-east-1a", "eu-east-1b"]
  public_subnets = ["10.0.101.0/24", "10.0.102.0/24", "10.0.103.0/24"]

  enable_nat_gateway = false
  enable_vpn_gateway = false

  tags = {
    Terraform   = "Yes"
    Environment = "Dev"
  }
}
### Creting windows server
module "ec2_instance" {
  source = "terraform-aws-modules/ec2-instance/aws"

  name = "windows-server"

  instance_type          = "t3a.xlarge"
  key_name               = "${aws_key_pair.kp.id}"
  monitoring             = false
  vpc_security_group_ids = ["${module.windowserver_sg.security_group_id}"]
  subnet_id              = "${module.vpc.public_subnets[0]}"
  ami                    = "ami-069c45f40acdfe41e"

  tags = {
    Terraform   = "Yes"
    Environment = "Dev"
  }
}

## Creating Linux server
module "ec2_linux" {
  source = "terraform-aws-modules/ec2-instance/aws"

  name = "linux-instance"

  instance_type          = "t2.micro"
  key_name               = "${aws_key_pair.kp.id}"
  monitoring             = false
  vpc_security_group_ids = ["${module.windowserver_sg.security_group_id}"]
  subnet_id              = "${module.vpc.public_subnets[0]}"
  ami                    = "ami-05548f9cecf47b442"

  tags = {
    Terraform   = "Yes"
    Environment = "Dev"
  }
}

#### Creating a Security Group that will allow RDP and SSH, Attaching this to both servers
module "windowserver_sg" {
  source = "terraform-aws-modules/security-group/aws"

  name        = "windowserver"
  description = "Security group made for moccing Windows server with forwarder"
  vpc_id      = "vpc-12345678"

  ingress_cidr_blocks = ["0.0.0.0/0"]
  ingress_rules       = ["rdp-tcp", "ssh-tcp"]

}
##### Creating the Key Pair
resource "tls_private_key" "pk" {
  algorithm = "RSA"
  rsa_bits  = 4096
}

resource "aws_key_pair" "kp" {
  key_name   = "winserver"
  public_key = tls_private_key.pk.public_key_openssh
}

resource "local_file" "ssh_key" {
  filename = "winserver.pem"
  content = tls_private_key.pk.private_key_pem
}

#### Creating the Local file with all the credentials and details

resource "local_file" "needed_details" {
  content  = <<-EOT
            Server IP:
            ${module.ec2_instance.public_ip}
            Admin Password:
            ${rsadecrypt(module.ec2_instance.password_data, file("./${local_file.ssh_key.filename}"))} 
        EOT
  filename = "./Windwos_details.txt"

  depends_on = [ local_file.ssh_key ]
}

though, while trying to run (plan/apply) I get the follwing error:

╷
│ Error: Invalid function argument
│
│   on main.tf line 93, in resource "local_file" "needed_details":
│   93:             ${rsadecrypt(module.ec2_instance.password_data, file("./${local_file.ssh_key.filename}"))}
│     ├────────────────
│     │ while calling file(path)
│     │ local_file.ssh_key.filename is "winserver.pem"
│
│ Invalid value for "path" parameter: no file exists at "./winserver.pem"; this function works only with files that are distributed as part   
│ of the configuration source code, so if this file will be created by a resource in this configuration you must instead obtain this result   
│ from an attribute of that resource.

I was reading the error again and again but I don’t understand how to implement the requirement in my code, how should i obtain a result from an attribute of the local file resource,

I was searching online and didn’t find anything like that, so a reference will be helpful aswell

Thank you all!