[Koha] Label Plugin (ByWater) - How to print a marc subfield?

I'm trying to configure a template on Label Plugin. I need to print a marc subfield, but it's not working.. When I try to use the following code [% item.marc.subfield('090','a') %] I receive the message below: Template process failed: undef error - Undefined subroutine &C4::Biblio::GetMarcBiblio called at /var/lib/koha/library/plugins/Koha/Plugin/Com/ByWaterSolutions/LabelMaker.pm line 438. How to solve that? Can you help me? [image: Mailtrack] <https://mailtrack.io?utm_source=gmail&utm_medium=signature&utm_campaign=signaturevirality11&> Sender notified by Mailtrack <https://mailtrack.io?utm_source=gmail&utm_medium=signature&utm_campaign=signaturevirality11&> 28/11/23, 09:13:23