This article shows you how to install a microSD card for Reolink Argus 3 Pro, Argus 3 2K and Argus 3E. Check it out if that's what you look for.
If you need to check the playback of video clips recorded by your camera, you may install a micro SD card in the camera. Here is a simple guide you could follow.
Step 1. Pull open the rubber cover on the SD card slot.
Step 2. Insert the SD card into the slot with a paperclip or your fingernail. Make sure it does not pop out.
Step 3. Don't forget to put the cover back. Here is a picture that shows you where the SD card slot is: