Export ePub with cover requires Window

[DPDmancul]

When exporting in batch mode (for example in continuous integration) with:

emacs --batch main.org --eval="(package-initialize)" --eval="(require 'ox-epub)" --funcal org-epub-export-to-epub --kill

if the keyword EPUBCOVER is set, the following error arises:

ox-epub eport error: (error Window system frame should be used)

Without the --batch argument the final file is correctly generated, but in some contexts (for example in docker on Gitlab CI) it is not possible to start Emacs with a GUI and the batch mode is the only available way.
Even with --no-x-resources instead of --batch there is the same problem.

Is there a way to allow exporting with a cover in batch mode?

org version: 9.5-b83ae59
emacs version: 27.2
platform: Linux
installed via: MELPA