How to contact the ISS Astronauts and have a chat

2 crossed dipoles

tune to 145.800mhz.

it is only a 3 minute window as they pass near Taiwan

300kms line of sight on vhf or UHF should do it

Or you could talk to them on vhf or uhf with a normal handheld radio, or boost your signal reception with a small antenna

Try not to do it when they are busy lol or taking a spacewalk