Hi,
Here is the tutorial to migration from Joomla 3 to Joomla 4:
docs.joomla.org/Joomla_3.x_to_4.x_Step_by_Step_Migration
As long as you have the latest version of HikaShop on your Joomla 3 website, you don't need to do anything for HikaShop if you follow that guide.
HikaShop is not a backup extension and doesn't have backup features, and there never was a one click backup and import button in HikaShop.
If you want to backup your website, you can use Akeeba Backup.
The "export database tables, import, copy to new tables and migrate images" method you're talking about is when you want to migrate a HikaShop from one Joomla website to another Joomla website, regardless of the version of Joomla on either websites.