How to deal with dirty neighbours in apartment

Hi! I recently moved into an apartment (purchased) and things have been stressful and on top of it today I noticed that one of my neighbours keeps their rubbish on their balcony. It’s attracting pigeons and flies and it smells bad. I don’t want it to get worse and deal with pests.

What’s the best way to deal with this? I’m a woman and live alone so I don’t want to be too confrontational since I don’t know what kind of person they are. Should I leave a note on their door or contact strata? The neighbours are renters I believe and been here for about a year.

Thank you!

EDIT: I looked closer at their balcony and I saw MAGGOTS 🤮🤮🤮 in their bin!!! Do I write a note or go straight to strata?