ALM Integration in AEM sites – Seamless login Experience

HI, We are integrated ALM in our AEM website. Having Login Page in our website and expecting login should happen in our website itself instead of redirecting to ALM login screen. We don’t have IDP. We need an API that allows us to authenticate registered learners on our website using their registered email addresses and passwords, rather than redirecting them to ALM. Do we have any direct API/Document to explain about the Learner’s authentication.