Samsung Galaxy J3 Luna Pro Tips and Tricks: The Ultimate Guide
Samsung Galaxy J3 (2017): How to insert the microSD card? Installation of a micro SD - YouTube
MicroSD cards and your Galaxy phone or tablet
How to install SD and SIM card into Samsung Galaxy J3 - YouTube
Amazon.com: Samsung Evo Plus 256GB Micro SDXC Memory Card Class 10 Works with Samsung Galaxy Phones J2 Core, J3 (2018), J4 Core (MB-MC256KA) Bundle with (1) Everything But Stromboli MicroSD/SD Card Reader :
Galaxy J3 2016 - How to insert micro SD card - YouTube