Extending Keycloak X with user storage spi provider

We have been using keycloak for a while but the wildfly version and now we are upgrading to keycloak X.
the way we use keycloak is by creating a user federation or user storage spi provider, and we run it in a docker container with keycloak x base image
the problem is that when i build the spi and copy the jar file into the /providers folder inside the docker container then in dockerfile i run /opt/keycloak/bin/kc.sh config, nothing happened and the spi is not installed.

I am looking at the documentation abou installing, enabling and configuring SPIs, but i got confused by the following syntax

<@kc.build parameters="--spi-email-template-mycustomprovider-enabled=true"/>

where should i put this code? is it in keycloak.properties?
so is there any other way to install the spi?