Problems with duplicate DOI numbers

My query lies in the following drawback. We had raised Vol 13 Series 2, but in the gallery we did not assign the Doi number
https://revistascientificas.una.py/index.php/stevia/index
When unpublishing and modifying the PDFs of the Galeras, it does not allow me to assign the DOI again
How could this inconvenience be solved?

Hi @mvillag,

Could you please indicate your OJS version number (e.g. 3.3.0-13). In the future, please include this in your posts, as it assists with those who are helping to troubleshoot.

Best regards,

Roger
PKP Team