How to make a route to network No. 3, through network No. 2 from network No. 1?

Question

Computer networks

Hello!
The question is banal, don’t scold too much, but I can’t argue myself
There are three networks:
Network No. 1
Zyxel Keenetic 4G
192.168.2.1 / 255
Combined with network No. 2 via VPN (PPTP) connection (the connection is assigned the address 172.16.1.2 in network No. 1) , the route, as I understand it, is created automatically (users of Network #1 easily go to network #2)
Network #2
Zyxel Keenetic Lite III
192.168.1.1 / 255
There is no route to network #1, but there is an IP2Sec connection to network #3 (the connection is assigned an address 192.168.1.145)
Registered route to network #3
Network #3
Mikrotik RB951Ui-2Hnd
192.168.59.1 / 255
Registered route to network #2

People from networks No. 2 and 3 go to each other without any problems.
The question is, what route and where should be registered so that people from network No. 1 (192.168.2.1) can get into network No. 3? (192.168.59.9)
Connection from network #1 directly to network #3 cannot be done due to the same external IP of network #2 and network #1 (Mikrotik leaves only one connection)

Answer 1

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