Not all countries or regions have a Microsoft-localized version of Business Central.
Refer to the list of supported countries and regions
https://learn.microsoft.com/en-us/dynamics365/business-central/dev-itpro/compliance/apptest-countries-and-translations
For them, it will be built on top of the international (W1) version.
By default, the caption is set to ‘VAT.’ However, today I’ll guide you through the process of renaming it to ‘GST.
Step 1: Go to ‘Extension Marketplace’
Step 2: Look for ‘Australia Language’
Step 3: Install the Extension
Choose the extension by Microsoft.
Step 4: Change ‘Language’
Use ‘English (Australia)’.
Now, it will be successfully renamed to ‘GST’ and you can search using ‘GST’.