4 WAN 1 LAN -- Radius server issue

RouterOS Forwarding Protocols
1

Hello All,
Dear friends, I’m having a problem with 4Wan 1Lan All is working properly and okay, but Radius server request is going to all WANs…What I want is…Radius request only goes form WAN1

2

Dear friends,
I need a solution please

3 
/ip route add gateway=wan1_gw dst-address=radius_ip