Welcome to the community!
A good start is this post: BraX3 Telco Compatibility – Rest of the World
For Rest of World region (non-US and non-EU), we are using a community-generated list, based on community feedback. We don’t have feedback for Singapore or Thailand, but the article has a general guideline on checking whether the device can connect locally (which doesn’t guarantee it). Since we have a return due to change of mind policy, you can try the product and return if it won’t connect, or if you’re unhappy for any other reason.