In beorg side, since these journal files have no extension, they can't be seen in beorg, hence impossible to create a template for them.
Is it possible in beorg to create a specific settings for downloading journal files which have no extension?
You can set org-journal-file-format to have org-journal include a file extension. I'm not an org-journal user myself (at the moment anyway!) so haven't tried this.
Can you use a script to create link files for all the org-journal files? Then run the script on (say) a 1 minute timer to check for any new journal files and create the link?
@Matthew, if you check README of org-journal for spacemacs, there is a warning stating changing org-journal-file-format breaks the search:
> Warning: setting org-journal-file-format to include a file extension like %Y-%m-%d.org would break the calendar search functionality.