Failed for Watchdata check in Linux - java.security.KeyStoreException: PKCS11 not found

I am trying to install and use the EMSigner app from the GST Portal on a linux machine.

Ref:

1. https://www.gst.gov.in/help/docsigner
2. https://www.gst.gov.in/system/#/sysreq-install-steps

While signing the website asks for the token key password, and after entering the password it fails with a message, "unable to load token"

Looking into the console log for emsigner I see the following error message

                                                                                                             
library =/usr/lib/WatchData/eMudhra_3.4.3/lib/libwdpkcs_eMudhra_343.so                                                                                                   
Failed for Watchdata check in Linux - java.security.KeyStoreException: PKCS11 not found                                                                                  
error msg==>>PKCS11 not found                                                                                                                                            
check==>>PKCS11 not found                                      

I am not sure what needs to be done for the S/W to find PKCS11.

My configuration is:

java -version
java version "1.8.0_261"
Java(TM) SE Runtime Environment (build 1.8.0_261-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.261-b12, mixed mode)

lsb_release -a
No LSB modules are available.
Distributor ID: Linuxmint
Description:    Linux Mint 20
Release:        20
Codename:       ulyana

My Hardware token is proxkey

i have a similar case.
the watchdata token used by the brazillian government is slightly different from yours, but i got it working with:

required for watchdata token

• these packages

apt install dkms libnss3-tools

web browser config

• chrome web browser (replace with the path to your library)

modutil -dbdir sql:.pki/nssdb/ -add "token-watchdata" -libfile /usr/lib/watchdata/ICP/lib/libwdpkcs_icp.so

• mozilla based web browser like firefox and palemoon (use the path to your library)

optional java support

• if you also need java support, it will only work on palemoon (or very old firefox releases).
• search on the internet for a file called libnpjp2.so and place it on /usr/lib/mozilla/plugins/

~:$ ls /usr/lib/mozilla/plugins/

libnpjp2.so

you also will need java packages

apt install default-jdk openjdk-11-jdk

~:$ java -version

openjdk version "11.0.8" 2020-07-14

and thats it. java + token module working on palemoon.
chrome doesnt support java, but will load the pkcs11 module.