Product plans: Premium feature, please connect to support@sell.do for commercial details.
Device: Android device v7.0 & above
From Support manager login Enable below Features Flags
-> Features
-> Features -> Enable Offline Dialer
-> Features -> Telephony
-> Features -> Telephony -> Call Settings - -> Download offline call recording.
Steps :
1. open Google Play Store and Search Sell.do Dialer / open Link & install the application
2. Launch the Application -> when Set default Phone App & click on Cancel button
3. Give all permission mentioned in image 
4. Login using your sell.do crm/mobile account 
5. After Signup your last 100 calls will be sync with Sell.do CRM automatically
6. Check if your device supports call recording which
Call Recording: The call recording that are exposed by the mobile phone will only be synced in the App/CRM (For Example: Samsung, Xiaomi, Vivo, LAVA etc)
set call recording path using "Use this Folder" option
7. Check and Validate if all permissions are given or Not.
Imp ->
1. When dialing/making any outgoing call make sure you are using your defualt dialer application and not Sell.do Dialer application
2. If Any call will failed to sync or not added in Sell.do Dialer application then it will automatically Upload to CRM in every 15 min as per Android Device Standard policy.
official Android Doc -> Open Link