Please visit the online portal for Emsisoft Mobile Security and log in with the Google email address you are using for our security app: https://central.emsisoft.com/
Please choose "My devices" from the menu on the left and look for the entry describing your older device, then click the three little dots in the upper right corner of the entry for the old device and choose "Remove" to remove it from your account.
On your newer mobile device you should only need to install Emsisoft Mobile Security from the Google Play Store and make sure to log in with your Google email address at the first start of the app.
Please note that if you installed our security app on your newer device already before performing the above steps then it can take up to 24 hours until the full version will be unlocked on the newer device automatically.
Alternatively you can uninstall Emsisoft Mobile Security from the new device, remove the old device entry from your online portal, then re-install on the new device and the changes would have effect immediately.