We've got the Galaxy S21 FE user manual, and a microSD slot is not mentioned - SamMobile
Use Micro SD Card & Expand Storage on Samsung Galaxy S21? #SHORTS - YouTube
Lector Tarjetas SD USB C 3 en 1 Adaptador USB C a Lector de Tarjetas SD Micro SD Card Reader & Adaptador USB-C a USB 3.0 para MacBook,Mac,Galaxy S21,iPad,Portátil,Tablet,Teléfono,U-Disk,Cámara etc : Amazon.es:
Does the Samsung Galaxy S21 have a microSD slot? | Android Central
Does Galaxy S21 FE support micro SD card or dual SIM
Samsung is ditching the microSD card slot on the Galaxy S21 line - CNET