Hi @kaeyee ,
There are 2 accepted formats when calling an international number:
Example: + 44 20 1234 5678
Example: 0011 44 20 1234 5678
You may click HERE (tpg.com.au/mobile#international-callrates) to check the country code.
For more details you may visit this article, TPG Mobile International Call Troubleshooting
Let us know how it will go and should you require further assistance.
What is the IDD code dial to Malaysia?