Does the JWT snap support password signing instead of public key?

We need to leverage a third party API that uses JSON Web Token (JWT) for authentication. We have created a PoC in Python that works fine. However, when trying to leverage the JWT snap with Snaplogic, we faced the situation that this snap required a public key-based account, while our provider uses a 10 character password for this. We wrote another short script in Java that uses nimbusds (as used by the snap) and jsontoken (as suggested by the provider). The later works fine, the former fails with a similar message as snaplogic (256 bit expected)

Can you confirm if we can use the JWT snap with a simple password (8-30 positions)?

If not, can we deploy a Java library (jsontoken) to the Snaplexes so we can leverage this library in a simple script?

Any other recommendations?

Thanks