Citric acid works great for this. A $10 bag will last the rest of your machine’s life, and there’s no weird aftertaste like can sometimes happen with vinegar.

You can get citric acid at most brew/winemaking stores that works fine.

I’ve always used vinegar to descale my coffee machine.

Espresso maker? Living close to edge aren’t you sport.

You can use citric acid too, or at least I did

Lactic acid is a no no though apparently

As long as your coffee mug still has 10+ years of black tar in it.