Both online update and offline update are available:

Online Update: Go to System > Maintenance > Upgrade, and the system will automatically check for updates. If there is an update package for a later version on the server, you can directly perform the online update. If no update packages are found, you will get a message that reads "This is the latest version.".

Offline Update: Go to System > Maintenance > Upgrade, and click Offline Update. In the step called Get Files Ready, click Upload to upload the update package stored locally. Then, complete the upgrade according to the instructions.