Using custom credential provider in Keycloak - keycloak

Question

I have created a custom credential provider PinCredentialProvider with a corresponding PinCredentialProviderFactory for Keycloak.
class PinCredentialProviderFactory: CredentialProviderFactory<PinCredentialProvider> {
companion object {
final val PROVIDER_ID = "pin"
}
override fun create(session: KeycloakSession): CredentialProvider<*> = PinCredentialProvider(session)
override fun getId(): String = PROVIDER_ID
}
class PinCredentialProvider(
private val session: KeycloakSession
): CredentialProvider<PinCredentialModel>, CredentialInputValidator {
override fun getType(): String = PinCredentialModel.TYPE
override fun createCredential(realm: RealmModel, user: UserModel, credentialModel: PinCredentialModel): CredentialModel {
if(credentialModel.createdDate !is Long) {
credentialModel.createdDate = Time.currentTimeMillis()
}
return getCredentialStore().createCredential(realm, user, credentialModel)
}
override fun deleteCredential(realm: RealmModel, user: UserModel, credentialId: String): Boolean =
getCredentialStore().removeStoredCredential(realm, user, credentialId)
override fun getCredentialFromModel(credentialModel: CredentialModel): PinCredentialModel =
PinCredentialModel.createFromCredentialModel(credentialModel)
override fun getCredentialTypeMetadata(context: CredentialTypeMetadataContext): CredentialTypeMetadata =
CredentialTypeMetadata.builder()
.type(type)
.category(CredentialTypeMetadata.Category.BASIC_AUTHENTICATION) // TODO is this correct?
.displayName(PinCredentialProviderFactory.PROVIDER_ID)
.helpText("pin credential provider")
//.createAction()
//.removable(false)
.build(session)
override fun supportsCredentialType(credentialType: String): Boolean = type == credentialType
override fun isConfiguredFor(realm: RealmModel, user: UserModel, credentialType: String): Boolean {
if(supportsCredentialType(credentialType).not()) return false
return getCredentialStore().getStoredCredentialsByTypeStream(realm, user, credentialType).count() > 0
}
override fun isValid(realm: RealmModel, user: UserModel, input: CredentialInput?): Boolean {
return true
}
private fun getCredentialStore(): UserCredentialManager = session.userCredentialManager()
}
It works fine and the custom provider is displayed on the server info -> providers page of Keycloak.
The question is now, how can I use the credential type for users: