This plugin is made for fast batch geocoding from JSON file with addresses.
Plugin works with Qgis v. 3.0 or higher. You also need your own HERE services API key. You can get it for free, it allows you do geocode up to 250 000 entries per month.
In order to install this plugin, put it into Qgis python plugins folder e.g
AppData\Roaming\QGIS\QGIS3\profiles\default\python\plugins