My code-first approach for SOAP in spring is not generating the XSDs and WSDL correctly

I've created a SOAP service by following this example pretty much to the letter:
https://dzone.com/articles/creating-a-soap-web-service-with-spring-boot-start

But I want to follow a code-first (bottom up) approach so rather than write the xsd and generate the java from it, I write the java and generate the xsd from it like so:

            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>jaxb2-maven-plugin</artifactId>
                <executions>
                    <execution>
                        <id>schemagen</id>
                        <goals>
                            <goal>schemagen</goal>
                        </goals>
                        <phase>generate-resources</phase>
                        <configuration>
                            <clearOutputDir>false</clearOutputDir>
                            <sources>
                                <source>../soapservice-api/src/main/java/techbasics/soapservice/api/v1</source>
                            </sources>
                        </configuration>
                    </execution>
                </executions>
                <configuration>
                    <verbose>true</verbose>
                </configuration>
            </plugin>

and then add the xsds to the classpath, which is then used to generate the wsdl. This works great except that the jaxb2-maven-plugin only picks up the objects annotated with java.xml.bind annotations like @XmlElement and so on, and so only generates "model" objects in the xsd files.

The problem is I don't know how to make it distinguish between model classes (which are generated fine) and the endpoint class containing the operations:

Model class:

@NoArgsConstructor @AllArgsConstructor @Builder @Data
@XmlType(namespace = SoapService.NAMESPACE_URI_V1)
public class Person {
	@XmlElement(name = "name")
	private String name;

	@XmlElement(name = "age")
	private int age;

	@XmlElementWrapper(name = "qualifications", nillable = true)
	@XmlElement(name = "qualification")
	private List<String> qualifications;
}

Service class:

public class SoapService {
    @PayloadRoot(namespace = "http://localhost:8000/soapService/v1", localPart = "processPerson")
    @ResponsePayload
    public ProcessedPerson processPerson(Person person) {
        //do stuff
        return return new ProcessedPerson();
    }
}

Generated XSDs:

schema1.xsd:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="http://localhost:8000/soapService/v1" version="1.0">

  <xs:complexType name="person">
    <xs:sequence>
      <xs:element minOccurs="0" name="name" type="xs:string"/>
      <xs:element name="age" type="xs:int"/>
      <xs:element minOccurs="0" name="qualifications" nillable="true">
        <xs:complexType>
          <xs:sequence>
            <xs:element maxOccurs="unbounded" minOccurs="0" name="qualification" type="xs:string"/>
          </xs:sequence>
        </xs:complexType>
      </xs:element>
    </xs:sequence>
  </xs:complexType>

  <xs:complexType name="processedPerson">
    <xs:sequence>
      <xs:element minOccurs="0" name="name" type="xs:string"/>
      <xs:element name="over18" type="xs:boolean"/>
      <xs:element name="numberOfQualifications" type="xs:int"/>
    </xs:sequence>
  </xs:complexType>

schema2.xsd:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" version="1.0">

  <xs:complexType name="soapService">
    <xs:sequence/>
  </xs:complexType>
</xs:schema>

Of course this generates a wsdl without any operations:

This XML file does not appear to have any style information associated with it. The document tree is shown below.

<wsdl:definitions
	xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"
	xmlns:sch="http://localhost:8000/soapService/v1"
	xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/"
	xmlns:tns="http://localhost:8000/soapService/v1" targetNamespace="http://localhost:8000/soapService/v1">
	<wsdl:types>
		<xs:schema
			xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="http://localhost:8000/soapService/v1" version="1.0">
			<xs:complexType name="person">
				<xs:sequence>
					<xs:element minOccurs="0" name="name" type="xs:string"/>
					<xs:element name="age" type="xs:int"/>
					<xs:element minOccurs="0" name="qualifications" nillable="true">
						<xs:complexType>
							<xs:sequence>
								<xs:element maxOccurs="unbounded" minOccurs="0" name="qualification" type="xs:string"/>
							</xs:sequence>
						</xs:complexType>
					</xs:element>
				</xs:sequence>
			</xs:complexType>
			<xs:complexType name="processedPerson">
				<xs:sequence>
					<xs:element minOccurs="0" name="name" type="xs:string"/>
					<xs:element name="over18" type="xs:boolean"/>
					<xs:element name="numberOfQualifications" type="xs:int"/>
				</xs:sequence>
			</xs:complexType>
		</xs:schema>
	</wsdl:types>
	<wsdl:portType name="SoapServiceV1Port"></wsdl:portType>
	<wsdl:binding name="SoapServiceV1PortSoap11" type="tns:SoapServiceV1Port">
		<soap:binding style="document" transport="http://schemas.xmlsoap.org/soap/http"/>
	</wsdl:binding>
	<wsdl:service name="SoapServiceV1PortService">
		<wsdl:port binding="tns:SoapServiceV1PortSoap11" name="SoapServiceV1PortSoap11">
			<soap:address location="http://localhost:8000/soapservice/v1"/>
		</wsdl:port>
	</wsdl:service>
</wsdl:definitions>

How can I generate the XSDs (and therefore the wsdl) correctly?