SSO with kerberos and openldap in docker

I am trying to create a testing env that would help me implement a SSO authentication using kerberos (production env is customers, so I don't have direct access to it). I started to setup an own env in a docker. Application is based on react in frontend and calls node.js REST API (express)

My plan is to setup

1. LDAP structure with users and groups
2. access LDAP from node.js backend
3. authenticate using fallback with LDAP username and password
4. setup KERBEROS with LDAP
5. add pc(win, mac) to domain
6. authenticate kerberos with ticket from browser

I successfully made steps 1-3. I am using a OpenLdap image for active directory which running in a docker (it is accessed by domain name lets say ldap.example.com ). I can manage users and groups, also I can access LDAP from backend with admin/tech user and retrieve data. I can authenticate user with his ldap username (uid) and password.

Problem is kerberos. I use kerberos docker image, and I am trying to setup it to authenticate a LDAP users.

krb5.conf

[libdefaults]
dns_lookup_realm = false
ticket_lifetime = 24h
renew_lifetime = 7d
forwardable = true
rdns = false
default_realm = LDAP.EXAMPLE.COM

[realms]
LDAP.EXAMPLE.COM = {
   kdc = ldap.example.com
   admin_server = admin
}

Another problem is add a PC to domain. I tried this only on mac. I can see Network Account server and I can successfully add it, but when I open Directory utility and I try to add active directory domain, it fail with a generic error Authentication server could not be contacted.

But main problem is a connection between a LDAP and kerberos image, I tried several several confiigurations but still cant figure out how to use ldap user credentials in a kerberos auth.