In order to create a file from the template and immediately save it as "Pretty JSON", you can use the "copy" module with the "content" key.
For example, save the template "config.j2" as the file "/app/config.json"
Playbook:
- name: Template a file to configuration files
copy:
content: "{{ lookup('template', 'templates/config.j2') | to_nice_json }}"
dest: "/app/config.json"
owner: artem
group: artem
mode: '0644'