How to properly organize routing between offices via VPN L2TP?

Question

VPN

Hi all.
Below is the network diagram:

The entire network is built on mikrotik. The main router and office routers are connected using L2TP VPN and have the following IPs 10.10.10.1 (main office), 10.10.10.2 (office 1) and 10.10.10.3 (office 2). Each office has its own subnet. The main office sees the subnets of each office and vice versa (routing is configured).
Question: how to set up routing between office 1 and office 2 (subnets 192.168.2.0/24 and 192.168.3.0/24 must see each other)?
The main office has a static IP address (for example, 15.15.15.15), but the offices are dynamic.

Answer 1

Raise OSPF everything else will work by itself.
Either:
1. Route to Office1 to the Office2 network through the Head Office (gateway = IP address of the head office in the tunnel or just a tunnel)
2. Route to Office2 to the Office1 network through the Head Office (gateway = IP address of the head office in the tunnel or just a tunnel)
3. Routes to the Head Office to Office1\2 networks through their IPs in tunnels or simply through these interfaces (gateway = l2tp_client
) do this through address lists and a script). Action=Accept in both cases. This is true for both OSPF and static routing.
By the way, you can watch my video. Maybe it will helphttps://www.youtube.com/watch?v=XSu5WfDeyiA

Answer 2

It turns out all these routes need to be registered on routers at offices?
Is the head office ready to be configured, since the vpn tunnel to each office is organized?