Expect Handwritten Signature without Default Fullname Signature

We are using

SignatureBuilder.captureFor()

to ask for a handwritten signature, but after the expected user signs, not only the handwritten signature drawn shows up, but also the full name appears, it seems the full name signature comes upon anyway by default. Is it possible to show the handwritten signature only? This is the sample code:

final SignerBuilder signer = SignerBuilder.newSignerWithEmail(email)
                    .withFirstName("sf9719")
                    .withLastName("Doe")
                    .withCustomId("Signer");
            final PackageBuilder packageToBuild = PackageBuilder.newPackageNamed("package");
            final DocumentBuilder document = DocumentBuilder.newDocumentWithName("pdf")
                    .fromStream(new ByteArrayInputStream(pdf), DocumentType.PDF)
                    .withSignature(SignatureBuilder.captureFor("[email protected]")
                            .withPositionAnchor(TextAnchorBuilder.newTextAnchor(esignSignatureAnchor)
                                    .atPosition(TextAnchorPosition.TOPRIGHT)
                                    .withSize(100, 100)
                                    .withOffset(10, 10)
                            )
                    );
            final DocumentPackage documentPackage = packageToBuild.withSigner(signer).withDocument(document).build();
            eslClient = new EslClient(esignAPIKey, esignAPIURL);
            packageId = eslClient.createPackageOneStep(documentPackage);
            eslClient.sendPackage(packageId);