Are chain certificates supported?

[DunklerPhoenix]

Heho
I try to use opensign.
Ref: OpenSignLabs/OpenSign#1376
If I use a pkcs12 certificate with ca chain I get the following message, but with certificates without chain it works.
Could it be that chain certificates are not supported by this library?

Greetings
Cy

server-1     | new entry is insert in contracts_Document
server-1     | Err in signpdf TypeError: Cannot destructure property 'publicKey' of 'certBags[i].cert' as it is null.
server-1     |     at /usr/src/app/node_modules/@signpdf/signer-p12/dist/P12Signer.js:66:9
server-1     |     at Array.forEach (<anonymous>)
server-1     |     at P12Signer.sign (/usr/src/app/node_modules/@signpdf/signer-p12/dist/P12Signer.js:64:27)
server-1     |     at SignPdf.sign (/usr/src/app/node_modules/@signpdf/signpdf/dist/signpdf.js:72:30)
server-1     |     at PDF (file:///usr/src/app/cloud/parsefunction/pdf/PDF.js:405:38)