External SignerVerification from Java to PHP

Hi, I need use external signer verification to register the sign and verify if is correct redirect the signer ceremony when Signer sign from PHP url. I have the code and structure necessary for create package and manage with Signers, documents and signatures and it's Works, the problem is that i don´t know how to add this feature to te process. I dons see the connection between eslPackage and this: https://docs.esignlive.com/content/c_integrator_s_guide/external_signer_verification/getting_started_with_esv.htm?Highlight=external%20signer%20verification Thanks a lot,