If your web application uses the SSL encryption, you need to capture HTTPS traffic instead of HTTP. To record HTTPS Traffic with JMeter, you need to configure the SSL certificates.
Configure your SSL proxy
Configure JMeter
Start script recording by using the “JMeter Recording Template” feature as explained in example "Script Recording with the JMeter Template Feature".
After opening the web application, you will see a message regarding an unsecure connection. To proceed, you just need to accept the JMeter dummy certificate:
This approach also works for mobile scripts recording, since the JMeter certificate needs to be installed only on the host which is being used to run JMeter.