pm2 resets list after reboot

[ailiusfx]

hello i have an issue.

if i type in my terminal: pm2 start mm.sh
and then after it typed: pm2 save
so the mm.sh script is in the pm2 list and should be saved.
but
if i reboot my raspberrypi my pm2 list gets cleared so it wont autoboot my mm.sh file.

if there a way to fix this issue?