"msg": "|結合には辞書が必要ですが、AnsibleUndefoundがあります。"

私のユーザーの役割を開始する際に問題があります。誰かを助けることができます。

「ユーザー」という次のAnsibleロールがあります。

    - name: Create required groups.
      become: yes
      group:
        name: "{{ item.1 }}"
        state: present
      loop: "{{ lookup('subelements', all_required_users|combine(required_users), 'groups', {'skip_missing': True}, wantlist=True) }}"
    
    - name: Create required users.
      become: yes
      user:
        name: "{{ item.key }}"
        state: "{{ item.value.state | default('present') }}"
        append: yes
        create_home: yes
        groups: "{{ item.value.groups | default([]) }}"
        password: "{{ item.value.password }}"
        shell: "{{ item.value.shell | default('/bin/bash') }}"
      loop: "{{ all_required_users | combine(required_users) | dict2items }}"
      when: "'state' not in item.value or item.value.state == 'present'"
    
    - name: Add ssh public key for required users.
      become: yes
      authorized_key:
        user: "{{ item.key }}"
        key: "{{ item.value.ssh_public_key }}"
        state: "{{ item.value.state | default('present') }}"
      loop: "{{ all_required_users | combine(required_users) | dict2items }}"
      when: "'state' not in item.value or item.value.state == 'present'"
    
    - name: Remove unwanted users.
      become: yes
      user:
        name: "{{ item.key }}"
        state: "{{ item.value.state | default('absent') }}"
        remove: true
      loop: "{{ all_required_users | combine(required_users) | dict2items }}"
      when: "'state' in item.value and item.value.state == 'absent'"

そして次のスクリプト：

    - name: install users
      hosts: 192.168.70.22
      become: true
      roles: 
        - role: users

)がプレイブックの実行を開始すると、次のメッセージが表示されます。

fatal: [192.168.70.22]: FAILED! => {"msg": "|combine expects dictionaries, got AnsibleUndefined"}

スクリプトが機能するにはどうすればよいですか？