Use of runtime variables to save into another variable using register in Ansible

- hosts: all
  tasks:
  - name: Ansible register variable basic example
    shell: "find *.txt"
    args:
      chdir: "/Users/mdtutorials2/Documents/Ansible"
    register: find_output

  - debug:
      var: find_output

#
- hosts: all
  tasks:
  - name: Ansible register with_items example
    shell: "find *.txt"
    args:
      chdir: "/Users/mdtutorials2/Documents/Ansible"
    register: with_output

  - shell: "cp {{ item }} {{item}}_bkp"
    with_items:
      - "{{ with_output.stdout_lines }}"