I am new to GraphQL and trying to implement graphql api with spring boot but facing error There is no scalar implementation for the named 'LocalDateTime' scalar type

pom.xml

<dependency>
    <groupId>.springframework.boot</groupId>
    <artifactId>spring-boot-starter-graphql</artifactId>
 </dependency>
 <dependency>
    <groupId>com.graphql-java-generator</groupId>
    <artifactId>graphql-java-server-runtime</artifactId>
    <version>2.8</version>
</dependency>
 
 
 <plugin>
    <groupId>com.graphql-java-generator</groupId>
    <artifactId>graphql-maven-plugin</artifactId>
    <executions>
        <execution>
            <goals>
                <goal>generateServerCode</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
       <schemaFilePattern>/graphql/emp.graphqls</schemaFilePattern>
        <targetFolder>target/generated-sources/graphql-java</targetFolder>
        <packageName>com.graphql.generated</packageName>
        <customScalars>
          <customScalar>
           <graphQLTypeName>LocalDateTime</graphQLTypeName>
           <javaType>java.time.LocalDateTime</javaType>
           <graphQLScalarTypeStaticField>com.graphql.config.LocalDateTimeScalar.createLocalDateTimeScalar
                    </graphQLScalarTypeStaticField>
        </customScalar>
       
      </customScalars>
      <copyRuntimeSources>false</copyRuntimeSources>
            <generateBatchLoaderEnvironment>true</generateBatchLoaderEnvironment>
            <separateUtilityClasses>true</separateUtilityClasses>
            <skipGenerationIfSchemaHasNotChanged>true</skipGenerationIfSchemaHasNotChanged>
    </configuration>
</plugin>

Custum Scalar class:

     public class LocalDateTimeScalar {

    private static final DateTimeFormatter FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    public static GraphQLScalarType createLocalDateTimeScalar() {
        return GraphQLScalarType.newScalar()
                .name("LocalDateTime")
                .description("Custom scalar for LocalDateTime'")
                .coercing(new Coercing<LocalDateTime, String>() {
                    @Override
                    public String serialize(Object dataFetcherResult) {
                        if (dataFetcherResult instanceof LocalDateTime dateTime) {
                            return FORMATTER.format(dateTime);
                        }
                        throw new CoercingSerializeException("Expected a LocalDateTime object.");
                    }
                    @Override
                    public LocalDateTime parseValue(Object input) {
                        if (input instanceof String dateTimeStr) {
                            try {
                                return LocalDateTime.parse(dateTimeStr, FORMATTER);
                            } catch (DateTimeParseException e) {
                                throw new CoercingParseValueException(
                                        "Invalid format. Expected 'yyyy-MM-dd HH:mm:ss'.", e);
                            }
                        }
                        throw new CoercingParseValueException("Expected a String value for LocalDateTime.");
                    }
                    @Override
                    public LocalDateTime parseLiteral(Object input) {
                        if (input instanceof StringValue stringValue) {
                            try {
                                return LocalDateTime.parse(stringValue.getValue(), FORMATTER);
                            } catch (DateTimeParseException e) {
                                throw new CoercingParseLiteralException(
                                        "Invalid LocalDateTime literal. Expected 'yyyy-MM-dd HH:mm:ss'.", e);
                            }
                        }
                        throw new CoercingParseLiteralException("Expected a StringValue for LocalDateTime literal.");
                    }
                }).build();
    }
    
    @Bean
    public RuntimeWiringConfigurer runtimeWiringConfigurer() {
        return builder -> builder.scalar(createLocalDateTimeScalar());
    }
    
}

Exception: graphql.schema.idl.errors.SchemaProblem: errors=[There is no scalar implementation for the named 'LocalDateTime' scalar type]