How to access public method in Opencart 4 extension controller?

Hello,
I create a sample payment extension for OpenCart 4. The front end controller is located at extension/sample/catalog/controller/payment/sample.php. I have two public method index() and test().
I can access the index() method using URL index.php?route=extension/sample/payment/sample, but I cannot access test() method. I tried index.php?route=extension/sample/payment/sample/test but it didn't work.
Can someone help me on this?

Thanks,

Should be: index.php?route=extension/sample/payment/sample.test