1 Product rec for fine 2c hair in humidity

Hey! This feels like I’m asking for a miracle but it’s worth a shot!

I’m backpacking Southeast Asia and only have space for 1 product.

I have fine, 2c hair and my main concern is frizz. Any product recommendations would be really appreciated!

In the humidity my hair just turns into one big puffball, so any other advice to help with this would be great too!

Thanks :)