Downloading and Installing/Upgrading Payment Plugin for J2Store
The next step is to login into your Joomla website administrator and navigate to the default Joomla installer page, Extensions => Manage => Install.
NOTE: You must have the J2Store component extension already installed and activated on your website before now; otherwise, the plugin installation will fail.
Follow the instruction on the Joomla installer page to upload and install the J2Store payment plugin you downloaded from our website.
After installation is complete, simply navigate to the J2Store Payment methods page, J2Store => Setup => Payment methods, to configure the installed payment plugin.