"ls -lsah $FWDIR/log/*.log" shows the firewall logfiles, fw.log is the actual and all others after a logswitch.
If the file is bigger then some kilobytes the logs are available locally on the appliance
12K -rw-rw---- 1 admin root 8.2K Nov 19 00:00 /opt/CPsuite-R81.20/fw1/log/2025-11-19_000000.log
30M -rw-rw---- 1 admin root 30M Nov 19 23:59 /opt/CPsuite-R81.20/fw1/log/2025-11-19_235900.log
12K -rw-rw---- 1 admin root 8.2K Nov 20 00:00 /opt/CPsuite-R81.20/fw1/log/2025-11-20_000000.log
12K -rw-rw---- 1 admin root 8.2K Nov 27 00:00 /opt/CPsuite-R81.20/fw1/log/fw.log
This shows the logs from the specified time range from logfile "2025-11-12_235900.log"
fw log -b "Nov 12, 2025 09:40:00" "Nov 12, 2025 10:00:00" 2025-11-12_235900.log
But if fw.log will be always small there are no logs locally available.