PHPRunner's REST action=view or insert

Hi.
I am using 10.91 and testing out PHPRunner's REST using Postman. I used the LIST action (i.e. action=list) and it returned the entire table.
http://localhost/api/v1.php?table=customers&action=list

I can even do the pagination using records, skip and search (q=).

However, it will not work for action=view or action=insert. It returns Error 500 and says "operation not supported".

It feels like I am missing something, certainly not authentication. Is there an extra security setting or something to enable for action=view or action=insert?

Many thanks in advance.

Kind regards