Web Application SSO and Active Directory

Question

I have a web application. I want to use the users and passwords in Active Directory when logging into this web application with SSO.
I want to use two methods here.
1- Providing login with SAML. There is enough documentation on this topic. There is no problem with this.
2- Developing my own agent application and sending the username and e-mail address information to my web application.
The problem is that when I develop my own application, I don't know exactly how the password verification process should be.
my guess about password authentication,

• Sending user and e-mail address information to the web application at certain times with the agent I have developed.
• Opening a socket from the agent and verifying the password entered in the web application with Active Directory. I don't know whether to use kerberos or a different method here.

As a result, I need helpful information for the design of the application that validates user information and passwords that I will develop myself.

Best regards,