From the attached screen shot, we are advertising our prefixes with our own ASN.
We now have a customer connected to our router 2, who has their own ASN and prefix.

We have already established bgp session with the customer to router 2, and the OSPF is redistributing Customers prefix to Router 1.
From Router 1 how do we advertise the Customers prefix and show their own ASN

Any help is really appreciated.

You need to use iBGP throughout your AS - redistributing in and out of OSPF for this kind of use case is something i'd avoid.

Here are config examples from a presentation I did:
https://mum.mikrotik.com//presentations/US13/kevin.pdf

Ideally you want a full table Route Reflector to take full tables and client prefixes and exchange them between a PE and the client router/AS

Here is a presentation I have on that topic:
https://mum.mikrotik.com/presentations/ ... 447941.pdf