Welcome to the RingCentral Community

Here is how you can setup the softphone in sandbox mode: https://developer.ringcentral.com/library/getting-started.html#ConfigureDevEnvironment

Could it be your other phone number is an international number? I have never seen a "no funds" message so I am not sure what could be the reason. Another way to create test calls and recordings is to add some new users to your sandbox account (https://service.devtest.ringcentral.com) and use different computers to launch the RingCentral softphone and making call between those computers. 

yes i had tried it, but when i am trying to call it's showing no funds,and i am tried from my phone and called to sandbox number it telling like number not exists

Hi Ashikh,

You can use the RingCentral softphone (https://www.ringcentral.com/office/features/softphone/overview.html) to call and receive call from any phone number. When you want to record a phone call, simply click the Record button on the softphone to start recording.

Remember to switch the softphone to "sandbox" mode if you want to use it with your sandbox account.

Hope this helps!
+ Phong