GALAXYSPAREPARTS For Galaxy Spare Parts SIM Card Tray + Micro SD Card Tray for Galaxy Tab A 10.5 inch T595 (4G Version) (Black) (Color : Black): Amazon.co.uk: Electronics & Photo
Amazon.com : PRITOM 10'' Tablet Android 10 Phone Tablet with SIM Slot, 64GB Quad Core, IPS Touchscreen, 8MP Rear Camera WiFi GPS Bluetooth USB C, Support 3G Phone Call, Black : Electronics
Is your SIM card inserted to the tablet correctly?
PRITOM 10'' Tablet Android 10 Phone with SIM Slot, 32GB Quad Core,... | eBay