Hello Hamood
R3 learns about 1.1.1.1 from R2. This can be seen in the output from the show ip bgp command executed on R3. The next hop IP is 192.168.23.2 which is that of R2. Also, when BGP neighbour relationships are configured, R3 and R2 are configured to be neighbours.
So the remove private-as command that’s implemented at R2 will have the result of removing the private AS’s from BGP updates from R2 to R3.
As a general rule, the remove private-as command is implemented on the router that is in a public AS but is directly connected to a router in a private AS. This way, private AS’s will not be propagated to the Internet.
I hope this has been helpful!
Laz