Backup Lightsail Instance Step By Step, Follow the These Simple Steps with screenshots to better understand.
Open the main Lightsail Instance Home Page Click on your Instance, You will see a Tab With 8 Options
Give Snapshot a name
Do Not Click Anywhere or Refresh the Window
To create a new Instance from a saved snapshot.
Create Automatic Backups in AWS Lightsail
Taking Backup of your Lightsail instance is simple and can be automated, you can get started with Lightsail for Free!
Always keep a snapshot for your configuration of a lower level to degrade the instance, because you may always upgrade to a higher configuration instance, but you can’t degrade.
With Configuration, I mean CPU’s & RAM, which means you may upgrade to 1Gb Ram from 512MB instance, but you can not degrade back to a 512MB instance with a snapshot of 1GB.
In one of my posts on WordPress, I have explained why you should never install cheap plugins without developer support on your WordPress sites.