Backup your current theme by selecting Actions > Duplicate (recommended)
Download the latest version on ThemeForest
Install the latest version and Publish
Regarding the app you have installed, you may need to reinstall them. We recommend that you contact the app provider for support as we cannot handle the code of the app.
If you want to use the latest theme and bring the data from the old version to the new version, here's how you can do it.
Themes don't update automatically, you need to do it manually
Migrate file settings_data.json
Open the old theme. Click Theme actions -> Edit code -> Open settings_data.json file -> Copy the entire code on this file. Then paste it into the same file of the new theme.
Click Save to finish.
Migrate file Index.json
Open the old theme. Click Theme actions -> Edit code -> Open index.json file -> Copy the entire code on this file. Then paste it into the same file of the new theme.
Click Save to finish.
You can do the same as you did with list files
product.json
collection.json