If your device has a built-in call recorder, which is usually the case on devices in India, Indonesia and Russia, you might be able to use the device's built in recorder as a recording source and Salestrail will just pick up the recording and store ot on the Salestrail app and in the dashboard.
To be able to determine whether you can use your built-in recorder as a recording source, you first need to determine whether your phone uses it's native dialer or a Google dialer. If your phone has a native dialer, you will be able to use the inbuilt recorder as the source for Salestrail, but if your device has a Google dialer, you will not. This is due to the fact that the call recording storage isn't accessible on phones with Google dialers.
To determine whether your device has a Google dialer, please follow the steps in this article: http://help.salestrail.io/en/articles/10002225-how-do-i-know-if-my-phone-has-a-google-dialer
Phones using a native dialer
If your phone has it's own native dialer (not a Google dialer) please follow the steps in this article to set up call recording on your device: https://help.salestrail.io/en/articles/10002260-call-recording-via-the-built-in-recorder
Phones using the Google dialer
If your phone has a Google dialer, please follow the steps in this article to set up call recording on your device: https://help.salestrail.io/en/articles/9258756-how-to-record-your-calls-using-the-salestrail-recorder-apk
If you are unsure of whether you have a built-in recorder on your device, please check this article: https://help.salestrail.io/en/articles/10002181-setting-up-call-recording-on-a-device-that-has-a-built-in-call-recorder