European Central Bank, quantitative easing and monetary policy

What is the role of the European Central Bank in the system of the European Economic Constitution? European Union has got a Central Bank but hasn’t a unitary government of the economy. After the 2008 crisis, the problem gradually emerged.
The European Central Bank has taken a completely new role. The Central Bank has adopted an innovative monetary policy. In 2015, during exceptional circumstances, the ECB decided to purchase the public debt of Member States (the so-called Public Sector Purchase Program). Both the European Union Court of Justice and the German Constitutional Court have ruled on this decision. In 2020, Bundesverfassungsgericht clarified that ECB’s acts had been ultra vires. It specified that it happened in exceptional circumstances.
What will be the role of the European Central Bank during and after the pandemic caused by the Covid-19 virus?