The cleanest recording comes from sharing only the slides, not your whole desktop. Viewers then never see your notes, other windows or pop-up alerts.
Google Slides
Open the deck in Chrome or Edge and share that tab in recorder.video. Start recording, go back to the tab and click Slideshow. With the tab audio box ticked, any video or sound in your slides is captured as well. Choose Presenter view from the Slideshow menu if you want your speaker notes in a separate window that stays out of the recording.
PowerPoint
To keep PowerPoint in a window, switch to Reading View from the View tab and share that window. On Windows you can also make the slide show itself play in a window under Slide Show > Set Up Slide Show > Browsed by an individual (window).
Keynote
Keynote’s usual slideshow fills the screen, so share the entire display it plays on. With two displays, play the slides on one, keep recorder.video on the other, and share only the slide display.
Full-screen slides on a single display
With only one screen, share the entire screen and start recording before you launch the slideshow. Close chat apps and turn on do not disturb first, because anything that pops up ends up in the video.
PowerPoint and Keynote can both show presenter notes on one display and the slides on another. Sharing just the slide display keeps your notes private.