TL;DR: Yes. But perhaps you need to reformat it.

Long story:
- if the phone says it is compatible with microSDXC: it should work as is. Samsung simply didn't officially certify more than 256GiB, because larger cards didn't exist back then. There is no technical reason why larger cards (up to 2TB) could not work.

- if the phone says it is compatible with microSDHC up to 32GiB: You will need to reformat. There is no hardware difference between microSDHC and microSDXC, the difference is software: out of the box, microSDHC come pre-formated as FAT32, and microSDXC come pre-formated as exFAT. If you phone is microSDHC, it doesn't have the driver to read exFAT partition, you will need to reformat the card into something that the phone can read (on older Androids that would be FAT32, ext4 or f2fs):
https://support.google.com/android...

I have a Samsung Galaxy A6 (even older than yours), and it works with a uSDXC 512 MByte card, but from a different manufacturer...(PNY)

Samsung Galaxy S9 et S9+ acceptent une capacité maximale de 400GB selon https://www.samsung.com/uk...