Using Bash trap when a command fails

example_trap.sh

#!/usr/bin/env bash

set -E

function log() {
  local      msg_args=("${@}")
  local      timestamp="$(date +'%Y-%m-%d %T')"
  declare -u log_level="${msg_args[0]}"
  local      message="${msg_args[@]:1}"

  echo -e "${timestamp} | ${log_level} | ${msg_args[@]:1}"
  curl -X POST \
    -H 'Content-type: application/json' \
    --data "{\"text\":\"${timestamp} | ${log_level} | ${message}\"}" \
    ## YOUR_WEBHOOK_URL ##
}

function fatal_log() {
  declare  -a  return_codes=("${PIPESTATUS[@]}")
  local    -r  array_length="$((${#return_codes[@]}-1))"
  local    -r  return_code="${return_codes[array_length]}"

  log fatal "Script ->${0}<- failed ->${var_on_trap}<- with return code ->${return_code}<- to on ->${BASH_LINENO[0]}:${BASH_COMMAND}<-"
  exit ${return_code}
}
trap fatal_log ERR

var_on_trap="test001"
curl invalid-url

ls -l
ls -l | grep aaa