Error when evaluating variable in import path: keystone_{{ keystone_web_server }}.yml.

root@ansible-master-staging-ussuri:/opt/openstack-ansible/playbooks# openstack-ansible os-keystone-install.yml -vv
Variable files: "-e @/etc/openstack_deploy/user_secrets.yml -e @/etc/openstack_deploy/user_variables.yml "
ansible-playbook 2.9.9
  config file = None
  configured module search path = ['/etc/ansible/roles/config_template/library', '/etc/ansible/roles/plugins/library', '/etc/ansible/roles/ceph-ansible/library']
  ansible python module location = /opt/ansible-runtime/lib/python3.8/site-packages/ansible
  executable location = /opt/ansible-runtime/bin/ansible-playbook
  python version = 3.8.5 (default, Jul 28 2020, 12:59:40) [GCC 9.3.0]
No config file found; using defaults
[DEPRECATION WARNING]: The TRANSFORM_INVALID_GROUP_CHARS settings is set to allow bad characters in group names by default, this will change, but still be user configurable on deprecation. This feature will be removed in version 2.10. Deprecation warnings can be disabled by setting deprecation_warnings=False in
ansible.cfg.
[WARNING]: Invalid characters were found in group names but not replaced, use -vvvv to see details
[WARNING]: Unable to parse /etc/openstack_deploy/inventory.ini as an inventory source
statically imported: /etc/ansible/roles/os_keystone/tasks/db_setup.yml
statically imported: /etc/ansible/roles/os_keystone/tasks/mq_setup.yml
statically imported: /etc/ansible/roles/os_keystone/tasks/keystone_pre_install.yml
statically imported: /etc/ansible/roles/os_keystone/tasks/keystone_install.yml
statically imported: /etc/ansible/roles/python_venv_build/tasks/python_venv_preflight.yml
statically imported: /etc/ansible/roles/python_venv_build/tasks/python_venv_wheel_build.yml
statically imported: /etc/ansible/roles/python_venv_build/tasks/python_venv_install.yml
statically imported: /etc/ansible/roles/python_venv_build/tasks/python_venv_set_facts.yml
statically imported: /etc/ansible/roles/os_keystone/tasks/keystone_post_install.yml
statically imported: /etc/ansible/roles/os_keystone/tasks/keystone_key_setup.yml
statically imported: /etc/ansible/roles/os_keystone/tasks/keystone_fernet.yml
statically imported: /etc/ansible/roles/os_keystone/tasks/keystone_db_sync.yml
statically imported: /etc/ansible/roles/os_keystone/tasks/keystone_credential.yml
statically imported: /etc/ansible/roles/os_keystone/tasks/keystone_federation_sp_shib_setup.yml
statically imported: /etc/ansible/roles/os_keystone/tasks/keystone_ssl.yml
ERROR! Error when evaluating variable in import path: keystone_{{ keystone_web_server }}.yml.

When using static imports, ensure that any variables used in their names are defined in vars/vars_files
or extra-vars passed in from the command line. Static imports cannot use variables from facts or inventory
sources like group or host vars.

EXIT NOTICE [Playbook execution failure] **************************************
===============================================================================
root@ansible-master-staging-ussuri:/opt/openstack-ansible/playbooks#

https://github.com/openstack/openstack-ansible-os_keystone/blob/eed5eb1fa1d52452bce72467530a1c86633e538e/defaults/main.yml#L192

keystone_web_server: "{{ (keystone_sp != {}) | ternary('apache', 'nginx') }}"

The configuration does not work, and the keystone_web_server need to be declared in user_vaiables.yml for the play to pass