Am I able to receive text messages when traveling to Asia?

Yes

but you need to have money in your wallet

Rate covers all countries in Zone Asia / Oceania

Is't not suppose to be free when receiving text and calls?

You are outside your coverage zone therefore you need to pay for it

You can buy Travel Add-on to use data and/or text only.

If you purchase a Travel Add-on for data, you will be able to use other apps (such as Textnow, Facebook, WeChat, etc) to make calls and text using your mobile data.