[Koha] Net::OAuth2::AuthorizationServer dependency is missing

[Zahid Iqbal]

 I have installed koha 19.05 on virtual machine in vmware station.
i have to activate api for koha for testing i have enabled
RESTBasicAuth,
RESTOAuth2ClientCredentials
RESTPublicAPI
these 3 parameter through Web services preferences are enabled
now when i saw on Perl modules in about.pl
Net::OAuth2::AuthorizationServer (0.16) is not installed.
and
it give me warning in
Preferences and parameters
*Warning* System preference 'RESTOAuth2ClientCredentials' is set, but the
required Net::OAuth2::AuthorizationServer dependency is missing. The
feature is disabled.
i have check the perl depancy in terminal
sudo apt-get install libnet-oauth2-authorizationserver-perl
and when i install through terminal it give me
libnet-oauth2-authorizationserver-perl is already the newest version
(0.17-1~koha+1).
anyone tell if i am doing wrong or some other issues in koha?
please can anyone give me any solution for enabling api and testing api.

Regards,

Zahid Iqbal