Request URI did not match SAML request destination

I am stuck with the following error:

ERROR [org.keycloak.adapters.saml.profile.webbrowsersso.WebBrowserSsoAuthenticationHandler] (default task-6) Request URI ‘https://private-ip:port/my-test-app/saml’ does not match SAML request destination ‘https:///my-test-app/saml’
2023-06-19 13:43:06,417 DEBUG [io.undertow.request.security] (default task-6) Authentication failed with message Authentication Failed and mechanism KEYCLOAK-SAML for HttpServerExchange{ POST /my-test-app/saml}

I am trying to authenticate using Azure AD, this is working fine. The issue I am facing is keycloak always redirects the authenticated user to the saml master ACS URL. However because my application is behind a reverse proxy, this is the private-ip of the application. I need to be able to have this as the destination in the SAML response, while redirecting to my proxy-ip/my-test-app/saml is this possible? How else does one authenticate a user in a web application behind a reverse proxy using keycloak and SAML?