It is not possible. If you send a packet out via WAN1 the remote service sees packets from that IP address and will return replies to the same address, you cannot force the remote service to return packets to a completely different IP address for WAN2.
I got it, thanks!
You can use policy-based routing so that conversations from different devices on your LAN use either WAN1 or WAN2 for sending or receiving, although defining the routing policy can be difficult.
This variant is suitable for me. I need to configure FILE SERVER in OFFICE1 to work on the WAN2.
WAN2 has a higher download speed.