Hi from the Swedish translation team.
It would have been great to show you the link to where we translate WordPress itself and (most of) the free plugins, namely: https://translate.www.ads-software.com/projects/wp-plugins/easy-wc-google-merchant-center-reviews/
But, unfortunately, the plugin developer needs to fix some problems in the plugin code before that can happen:
1. Every call to the translation functions should use a different plugin-textdomain. Instead of se-wc-google-reviews the plugin slug should be used, i.e. easy-wc-google-merchant-center-reviews
2. Also: The trunk/readme tag “Stable tag: 1.0.3” means that there SHOULD BE a directory /tags/1.0.3/ If you want the plugin to be built from trunk, then please use “Stable tag: trunk” instead.
Now, over to @plue
You can probably get it working by using languages/easy-wc-google-merchant-center-reviews.pot to create a Swedish translation, using poedit (standalone computer program) or Loco Translate (WordPress plugin).
Once you’ve got a translation, you need to generate a .mo file, name it easy-wc-google-merchant-center-reviews-sv_SV.mo and upload it to wp-content/languages/plugins/