Mongo DB not integration with Micronaut

I am creating one Micronaut application integrating MongoDB. Instead of providing a single line uri for connection string, I am building the connection string in the config class using properties like “host”, “username” & “password”. This connection string is used in the same class to create a MongoClient bean. But when i start the application and hit one endpoint from postman, I am getting the follwowing error as follows:

Error instantiating bean of type [io.micronaut.data.mongodb.operations.MongoDatabaseNameProvider] Message: Could not resolve placeholder ${auto.test.resources.mongodb.uri} Path Taken: MongoDatabaseNameProviderFactory.primaryMongoDatabaseNameProvider(DefaultMongoConfiguration mongoConfiguration,BeanContext beanContext,RuntimeEntityRegistry runtimeEntityRegistry,SchemaTenantResolver tenantResolver) → MongoDatabaseNameProviderFactory.primaryMongoDatabaseNameProvider([DefaultMongoConfiguration mongoConfiguration],BeanContext beanContext,RuntimeEntityRegistry runtimeEntityRegistry,SchemaTenantResolver tenantResolver) io.micronaut.context.exceptions.BeanInstantiationException: Error instantiating bean of type [io.micronaut.data.mongodb.operations.MongoDatabaseNameProvider]

Can anyone suggest what I am supposed to do here?