Swapfile and swap-partitions are rarely used now-a-days. But they still have one major use case which is hibernation. Use the following Commands to create and enable swapfile
Commands
sudo fallocate -l 6G /swapfile
sudo chmod 600 /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile
then change fstab (/etc/fstab) so it automatically mounts your swap file on startup
/swapfile none swap sw 0 0
Afterward, check if your swap file is operating properly with htop.
Swap can degrade SSD performance overtime so keep that in mind.