Authenticating to V6 API

Hi, previously if I issued the commend:

http://192.168.101.23/admin/api.php?topItems=10&auth=f13dedb16605499.......cce0be52a93

I got this response:

{
"top_queries": ,
"top_ads":
}

it's a new instance so no data yet but the json data returned is valid

Now if I try with the old token, or a hash of the current password, or an application password I get the following results:

<?xml version="1.0" encoding="iso-8859-1"?> 404 Not Found

404 Not Found

If I put in a random set of characters for the token I get the same results as above

I need to know how to make the base request with authentication then I can modify for the other API endpoints

Thanks,