firewalls log routes in SDWAN architecture?

Hi,

A customre built a sdwan architecture where 40 sites send logs to fortianalyzer behind a central Firewall.

when integrating fortianlyzer with remote sites' firewalls, the routes choosen by firewall are random and do not choose sdwan interfaces that were configured, it chooses one wan interface to send traffic logs,.... to fortianalyzer. is there any way to make fortigate logs chosse sdwan interface for Nospof purpuise? we tried to configure 2 tratic routes and it works but I thought there could be a way to configure traffic logs be sent through sdwan as it is already configured.

thank you.