First, check LibreElec version from os.libreelec.tv addon:
/usr/share/kodi/addons/http://os.libreelec.tv/addon.xml
XML
<?xml version="1.0" encoding="UTF-8"?>
<addon id="os.libreelec.tv" version="7.0" provider-name="LibreELEC.tv">
<requires>
<import addon="xbmc.addon" version="12.0"/>
</requires>
</addon>
Then, edit addon.xml inside the zip file and replace os.openelec.tv with os.libreelec.tv and corresponding version, within the requires section. In my example: