How do I use RingCentral dialer with the developer account?

Can someone please help with how to test the OAuth? Is there a RingCentral dialer that I should use to test?

Open this link and download the RC Phone (Desktop) app for Windows or MacOS accordingly. Install the app and run it. Switch the app to sandbox mode before login by:

On Windows: Ctrl + F2

On MacOS: Fn + Command + F2

Thanks for the response, Vu . I already had this app installed on my Mac. When I press Fn+Command+F2 (before login) nothing happens in the is it supposed to open a different UI?

I tried login after pressing Fn + command+F2 and the login just hung with a spinning "Please Wait" message

I believe i have the right app install (RC Phone desktop for Mac)

If I click Fn+Command+F2 the screen just stays as is

when you press those combined keys, you should see a small popup like this. Then choose the "sandbox" option.

I have reinstalled and now I see the popup for Sandbox/Produciton and I logged into my Sandbox. From here if I make a call to a regular mobile number, I dont seem to be receiving the call.

Should I expect this call to work?

Call to U.S number or international? Sandbox does not support call to international numbers. You will have 500 mins free out of the box for testing voice call. It's a new sandbox, I don't think that you run out of free credit though.

I am calling an us number. Should expect the normal phone to work or will only go directly to through the developer api. Sorry for the really basic question. I am new to Ringcentral.

I don't know what you meant here "Should expect the normal phone to work or will only go directly to through the developer api".

What is your sandbox main company number?

Just to clarify: I using the RingCentral Phone dialer to call a regular phone. Will this call come the phone directly?

Main Company number: +15648882482

Sandbox number: +14243302166