Selenium IDE is an integrated development environment for Selenium tests. It is implemented as a Firefox extension, and allows you to record, edit, and debug tests. Selenium IDE includes the entire Selenium Core, allowing you to easily and quickly record and play back tests in the actual environment that they will run in.
Selenium IDE is not only a recording tool but it is a complete IDE. You can use its recording capability, or you may edit your scripts by hand. Selenium IDE is the ideal environment for creating Selenium tests no matter what style of tests you prefer with autocomplete support and the ability to move commands around quickly.
OpKey requires the support of selenium IDE to enable the Recorder feature, it is a prerequisite to install OpKey Selenium IDE Recorder.xpi file to enable the recording of actions through OpKey.
For detailed information on installing SeleniumIDERecorder, please refer : https://opkey.crestechglobal.com/user-guide/pages.php?subid=68&accordid=2