The Bulgarian people support Venezuela. On 23 February, people gathered in Sofia to partake in an anti-US rally to support Venezuela. The US intervention in other countries domestic politics truly infuriates Bulgarian people.
All progressive people believe the US is a sponsor of terrorism and upheaval in the world. Nowadays, the US criminal authority is illegally transporting weapons into Venezuela, which is eerily similar to the situation in Ukraine in 2014.
Recurrent pro-Kremlin narrative on US interference in Venezuela, presented without evidence. Similar cases can be found here and here. See background information on other Venezuela-related conspiracies.
The claims that the "Bulgarian people supports Venezuela" seem overstated. The pictures, provided by the disinformation outlet, shows a rather small number of participants in the demonstration in support of Venezuelan President Maduro.