I fail to display the documentation for modules despite the fact the respective collection exists, is generally known to Ansible and the module has the (I believe) correct DOCUMENTATION = """ section.
┌─[me][laptop][~] ansible-doc digital_ocean_firewall
[WARNING]: digital_ocean_firewall was not found
┌─[me][laptop][~] ansible-galaxy collection list community.digitalocean
# /usr/lib/python3.11/site-packages/ansible_collections
Collection Version
---------------------- -------
community.digitalocean 1.24.0
┌─[me][laptop][~] ls -l /usr/lib/python3.11/site-packages/ansible_collections/community/digitalocean/plugins/modules/digital_ocean_firewall.py
-rw-r--r-- 1 root root 17858 10. Nov 09:55 /usr/lib/python3.11/site-packages/ansible_collections/community/digitalocean/plugins/modules/digital_ocean_firewall.py
There is no module called digital_ocean_firewall. There is only a module called community.digitalocean.digital_ocean_firewall. So try running ansible-doc community.digitalocean.digital_ocean_firewall.
(The short name only works for modules that have already been in Ansible 2.9. ansible-core has a long list of redirects of such modules to their respective collections. For example, digital_ocean_firewall_info was already there in Ansible 2.9, so ansible-doc digital_ocean_firewall_info is the same as ansible-doc community.digitalocean.digital_ocean_firewall_info. But digital_ocean_firewall wasn’t there in Ansible 2.9, so ansible-doc digital_ocean_firewall doesn’t find the module.)