This will be the only option on some operating systems, where there is no Panopto Recorder software (such as Linux).
You will need to record your lecture content using some other software, and then upload it to the Lecture Capture site. Go to the Lecture Capture website, and choose “Create -> Upload Media”. Your file should be a mp4 file. Once it is uploaded into Panopto, you can follow the editing and post-production instructions in the separate links on the side of the main Panopto guidance page.
On Linux, to record pdf slides with audio, you could use the Kazam application and a microphone. If you also wanted to display a webcam feed of yourself you could use guvcview. A brief demonstration of that is below.
On Linux, to record live handwriting with a visualiser, you could use the software OBS Studio to record the video stream.