aws ec2 ubuntu : why a command works with terminal BUT not with user_data?

i lanched an ec2 instance (ubuntu), and i have a script which looks like :

#!/bin/bash

# works fine (even directly in terminal or via user_data)
hostnamectl set-hostname ${hostname}

# works fine as well (even directly in terminal or via user_data)
echo "127.0.0.1 ${hostname}" >> /etc/hosts

# it works in terminal BUT NOT via user_data, why ?
curl -LsSf https://astral.sh/uv/install.sh | sh

i want to install uv (python package) with last code in my script above BUT it does not works using user_data, why ?

Update : This script named and located at remote-servers-script/installer.sh, and referenced in a terraform module which looks like :

  module "virtual_machine" {
  source        = "./virtual_machine"
  ami_id        = var.ec2_ami_id
  instance_type = "c7i-flex.large"

  for_each                      = toset(var.vms_names)
  public_key                    = var.public_key
  tag_name                      = each.key
  enable_public_ip_address      = each.key == "jump-server" ? true : false
  sg_for_jump_server            = each.key == "jump-server" ? [module.security_group.sg_ec2_jump_server] : [module.security_group.sg_ec2_clickhouse_instances]
  subnet_id                     = each.key == "jump-server" ? tolist(module.networking.free_iliad_public_subnets)[0] : tolist(module.networking.free_iliad_private_subnets)[0]
  user_data_install_jump_server = templatefile("./remote-servers-script/hostname.sh", { hostname = each.key }) # <== referenced here
}