f5 token based authentication using uri module throw error

using below yml file with header as below and token is variable authx . error i am getting is "authx is undefined"

is the header correct ?

 ---
- name: "{{ name }}"
uri:
url: "{{ url }}"
method: "GET"
headers:
X-F5-Auth-Token: "{{ authx }}"
validate_certs: "no"
status_code: "{{ status|default(200) }}"
timeout: 60
ignore_errors: True
delegate_to: localhost

JRahm