Hi Corinner,
Yes, Samsung water filters are single-use only. Once the filter has been used (up to 300 gallons or 6 months, whichever comes first), it must be replaced with a new genuine Samsung filter. You cannot reuse the old filter.
If you remove the filter from its slot or pocket, it is not designed to be reinserted. Putting it back could cause leaks or water spraying, because the filter seal and internal components are meant for one-time use only.
For replacement, the water supply line must be turned off, and then the old filter is removed and a new one is installed. Samsung provides step-by-step instructions here:
How to replace the water filter in a Samsung refrigerator:
https://www.samsung.com/us/support/answer/ANS10005090/
Leo