SSO between SAP Cloud Platform(SCP) and S/4 hana On premise

Dear Experts,

We have developed an Hybrid app and are using web dispatcher service to access odata service at backend.Now we want to map the SCP user ID to the S/4 on premise system.It is an embedded system(S/4 Hana on premise). We are aware of the SAP Cloud Platform and SCI(SAP Cloud identity) Authentication using SAML 2.0 certificates.

kindly help us know how to we achieve SSO between SAP Cloud Platform(SCP) and S/4 hana On premise using Web dispatcher ?

Thanks & Regards

Yamini