It used to work in Debian, but it doesn’t seem to work anymore in libreoffice 6 nor 7 on debian 10 not ubuntu 20.04 LTS
In Windows 10 it still works excellent with libreofice 7
In Debian 10 (with both libreoffice 6 and 7) the main problem is: certificate manager can see the certificate to sign but libre-office can not select the certificate.
This is the certificate
But libreoffice can not select it:
What can I do to get it, like it is possible on windows 10 and used to work until june/july last year on Debian 10