Using xsodata service with SAP HANA XS Engine without authentication

I have to use xsodata service with HANA XS Engine and I have created .xsaccess file inside Global folder as below:

{
    "exposed": true,
    "authentication" : null
}

I have the following test service created with below content:

service namespace "test.services" {
    "TESTUSER1"."sampledb" as "sampledb";
}

However I get 403 error, when I hit the URL: /test/services/test.xsodata/testdb. Now for validation I created a html file in same folder as test.xsodata and it works file when I hit this link. I tried adding .xsaccess file in Services folder and also added the above code however error remains same.

To troubleshoot it further, I added services/.xsaccess with this content:

{
    "exposed": true,
    "authentication" : [{"method":"Basic"}]
}

This prompts me to enter user name/password and when I enter credentials correct data is displayed. I am not sure what is wrong and why it is not working?

Anyone can help?