PSA: The 5G Galaxy S10 does not have a microSD slot - SamMobile
Amazon.com: SanDisk 256GB SDXC Micro Ultra Memory Card Works with Samsung Galaxy S10, S10+, S10e Phone Class 10 (SDSQUAR-256G-GN6MN) Bundle with (1) Everything But Stromboli Multi slot SD and Micro Card Reader :
Best microSD cards for the Samsung Galaxy S10 family of smartphones
For Samsung Galaxy S10 S10 Plus Sim Card Slot Sd Card Tray Holder Adapter - Sim Cards Adapters - AliExpress
Amazon.com: 32GB Micro SDHC EVO Plus Bundle Works with Samsung Galaxy S10, S10+, S10e Phone (MB-MC32) Plus Everything But Stromboli (TM) Card Reader : Electronics
How to Insert or Remove SIM and microSD cards into your Samsung Galaxy S10 Plus – The Droid Guy