GET signingUrls for agreement is failing in application

Hi!

I'm working on creating of test application for AdobeSign integration C#.

When I'm trying the call in "try it" page (REST API — Document e-signature Software — Adobe Sign), I'm getting the following response:

Request URL

https://api.na2.echosign.com:443/api/rest/v6/agreements/CBJCHBCAABAASHXLhpnMlIeuA2Pi3S7ewnID8yF8Qq4r/signingUrls

Response Body

{ "signingUrlSetInfos": [ { "signingUrls": [ { "email": "someaddress@somedomain.com", "esignUrl": "https://secure.na2.echosign.com/public/apiesign?pid=CBFCIBAA3AAABLblqZhDurMB28N5za2IxNYmueyExUE7WJa4rOkBdiLuIsl78c08sy12rbHyhu-3rh6BlpbI*&client_id=CBJCHBCAABAAjipHE56ILK-vpGLxT7lgDjXfeBYttICf" } ] } ] }

But when I'm trying to get the same call working in c#, I'm getting resource not found response. Here is my code:

            var client = new RestClient(adobesignURL + "/agreements/" + agreementID);

            var request = new RestRequest("signingUrls", Method.GET);

            request.AddHeader("Authorization", "Bearer " + adobesignIntegrationKey);

            var resp = await client.ExecutePostTaskAsync(request);

If I copy request URL when stepping through the code, it's working properly in Insomnia. What can cause the issue?