Hi marcouzi,
Thank you for your purchase and support.
You should be able to run fuzzylite from Terminal using:
cd Downloads/QtFuzzyLite Or wherever you downloaded and decompressed the software.
sh QtFuzzyLite.sh To run QtFuzzyLite
The version in the Ubuntu Software Centre is very old. The license you have purchased will give you access to the latest QtFuzzyLite 5.
Cheers.