How to set Sticky Session in NGINX in K3S?

I have successfully ran k3s with 2 nodes and several pods, and now I would like to make sticky session. How to do this?

Basically, there are multiple instances of NGINX in each pod, and my PHP app is using $_SESSION to store some data. But each time, a user connects to the k3s service, sometimes the user is sent to a different pod. This causes them unable to continue with their session. Reading around online, I see people mentioning “sticky session” which basically “locks” a user to the same pod. Can this be done in k3s?

Alternatively, are there other solutions to tackle this issue?

Thank you