“Gas is fungible and can be bought from any producer in the world.”
The problem is transport.
It takes years to get the infrastructure in place, and LNG tankers are not a solution.
As Germany has learned, even building gas storage is a process that can take a decade or more, due to the inane enviro laws they have saddled themselves with.
They could also use coal, which they have plenty of. But they're hell-bent on strangling their economies.