One way to get the swap usage on macOS is through sysctl,
$ sysctl vm.swapusage
vm.swapusage: total = 2048.00M used = 339.25M free = 1708.75M (encrypted)
or to get the virtual memory statistics, use vm_stat,
$ vm_stat
Mach Virtual Memory Statistics: (page size of 4096 bytes)
Pages free: 22689.
Pages active: 1293975.
Pages inactive: 1210689.
Pages speculative: 90024.
Pages throttled: 0.
Pages wired down: 1149514.
Pages purgeable: 45249.
"Translation faults": 627071029.
Pages copy-on-write: 17768756.
Pages zero filled: 444351056.
Pages reactivated: 10794611.
Pages purged: 764381.
File-backed pages: 1352224.
Anonymous pages: 1242464.
Pages stored in compressor: 1408501.
Pages occupied by compressor: 427131.
Decompressions: 6806364.
Compressions: 10983871.
Pageins: 102270242.
Pageouts: 7852274.
Swapins: 1883954.
Swapouts: 2043277.
It is generally not advisable to disable swap on macOS, and there's usually no need to manually increase the swap file's size.
This question/answer at the Ask Different site talks about moving the swap file to another disk, but the question is over eight years old, so it may be out of date.