Step 1: get Genymotion to use Charles (copied from this ref)

In your Genymotion Android emulator…
Settings -> Wifi -> Press and hold your active network
Select “Modify Network”
Select “Show Advanced Options”
Select “Proxy Settings -> Manual”
Set your Proxy to: 10.0.3.2 (Genymotion’s special code for the local workstation)
Set your Port to: 8888
Press Save

Step 2: Add SSL endpoint inside Charles

Charles -> Proxy -> SSL Proxying Settings, add the URL endpoint

Step 3: Add SSL certificate inside Android

Inside Genymotion, using Android’s browser, visit http://www.charlesproxy.com/getssl and install the certificate.

Step 4: There is no step 4.