Checking for multiple conditions using “when” on single task in ansible

I want to evaluate multiple condition in ansible using when, here is my playbook:

- name: Check that the SSH Key exists
   local_action:
     module: stat
     path: "/home/{{ login_user.stdout }}/{{ ssh_key_location }}"
   register: sshkey_result

 - name: Generating a new SSH key for the current user it's not exists already
   local_action:
      module: user
      name: "{{ login_user.stdout }}"
      generate_ssh_key: yes 
      ssh_key_bits: 2048
   when: sshkey_result.rc == 1 and  ( github_username is undefined or github_username |lower == 'none' )

here is my var file for reference:

---
vpc_region: eu-west-1
key_name: my_github_key
ssh_key_location: .ssh/id_rsa.pub

When I try to execute this playbook, I am getting this error:

TASK: [test | Check that the SSH Key exists] **********************************
ok: [localhost -> 127.0.0.1]

 TASK: [test | Generating a new SSH key for the current user it's not exists already] ***
 fatal: [localhost] => error while evaluating conditional: sshkey_result.rc == 1 and  ( github_username is undefined or github_username |lower == 'none' )

        FATAL: all hosts have already failed -- aborting

Can somebody point me out that how we can use multiple conditions with ansible on single task.

Thanks