It's easy to contact them through messaging apps. There's also a video call where you can call them and talk to them while seeing each other virtually.
A simple call or text will make them appreciate you more.
Yes, in this digital age, there are so many apps that you can use now to connect with someone. Video calling nowadays, is just a normal thing to do to have a conversation face-to-face. The internet connection is also getting cheaper these days. If they don't have one, they can always rent for few minutes to hours in a computer shop. You can always find a way how to communicate with them these days. We are not in the stone age anymore or maybe, snail mail