Why are the Wagner Group’s fingerprints all over the Niger coup?

This is the first major time the Wagner Group has emerged since its failed coup attempt against Moscow in June

 
Coup leaders in Niger have refused requests from other African leaders to reinstate the ousted President.

Instead they have decided to close its airspace under the threat of military retaliation from neighbouring countries.

But amid all the protests and action on the streets, people are waving Russian flags and chanting for France to leave the country.

Furthermore, the Wagner Group has emerged in this conflict for the first time since its failed coup against Moscow.

So what is it doing there, and what does it mean for the Russian war?