1. All the Reolink PoE and WiFi IP cameras coming with the SD card slot have the Overwrite option.
2. As for the Battery-powered cameras, the models which can support the Human/Vehicle detection (Argus 3, Argus 3 Pro, Argus PT 2K, Reolink GO Plus, Reolink GO PT Plus, Reolink Duo, Reolink Duo 4G) also have the Overwrite option for configurations, but the previous cameras like Argus 2, Argus Eco, Argus Pro, Argus PT, Argus 2E, Reolink GO, Reolink GO PT are set to overwrite the old files automatically, so there is no such option for these cameras on Reolink software.
For enabling/disable Overwrite option, please refer to How to Set the HDD to Overwrite Old Files