---
- name: Delete AWS keypair
  hosts: localhost

  vars:
    aws_key_name: aws-test-key

  tasks:
    - name: Fail if variables not defined
      ansible.builtin.assert:
        that:
          - aws_key_name is defined
          - create_vm_aws_region is defined
        fail_msg: "Required variables not set"

    - name: Delete AWS keypair
      amazon.aws.ec2_key:
        name: "{{ aws_key_name }}"
        region: "{{ create_vm_aws_region }}"
        state: absent

...