Best memory expansion gadget for iPhone XS

What is the best memory stick or flash drive for the iPhone XS? My 64gb phone is almost out of memory. Although I have all photos and videos automatically saved to Google Photos, I would like to save all memories imemory stick or flash drive for the iPhone XSn a gadget that I can hold on to in case Google decides to make these pictures and videos nonlonger accessible. The Sandisk seems to be a popular choice but the bad reviews state that it is not compatible with the iPhone XS. I would appreciate honest and candid opinions regarding the best 128gb and/or 256gb memory stick or flash drive for the iPhone XS. Thanks in advance for your time.