This error I got

HttpRequest cannot load http://localhost:57772/api/project. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:57773' is therefore not allowed access. The response had HTTP status code 401.

I use default web server has been used by Management Portal.

Can you please show screenshots or links?

It accepts only Get method. If I give another method, it shows 'Method not allowed'.

Why the method doesn't accept the post or put or delete method?

I tried the Demo.REST.MathService.cls  and I also configured the web server.

in that program, they mentioned Dispatch class as EnsLib.REST.Service, so I  added it

I tried in the both link.

http://localhost:57772/csp/ENSDEMO/rest/2/3

http://localhost:57772/csp/ENSDEMO/rest/sum/2/3

I couldn't run the program

Ok Gery. 

I need one small sample or example,

If you have it, can you share it?

I'm in confused.

Thanks Dmitry and John

I missed the Dispatch Class

ok, thanks Tomas and I have one question.

Is it possible execute this URL http://localhost:57772/csp/samples/docserver/namespaces in PostMan?

Is it possible execute this URL http://localhost:57772/csp/samples/docserver/namespaces in PostMan?

And I tried the first URL http://localhost:57772/csp/samples/REST.DocServer.cls, still, now it shows me the same error.

This is an example program for rest services[ REST.DocServer ], already given in 'samples' namespace.