Looking for the right place to post my apartment for rent

Hello all,
Sorry if this isn’t the right place to ask, but I’m looking for some advice. My landlord and I are pretty close, and since I’m moving back to my country at the end of the year, he asked me to help find a new tenant for his apartment. This isn’t a problem for me and I’m happy to help, but I’m not sure where to start or where to post it.
He prefers a foreigner or a student as a tenant, so ideally I’m looking for a place that targets that kind of audience, maybe a student housing site or something similar. I’d appreciate any suggestions, or sites you know of where I could post this.

Thanks!