Extending charging cables is a pretty hot business, even extending an emergency charger for EVs or plug-in hybrids is a no-go, the currents that can flow are not to be underestimated. In the worst case, you risk a cable fire. An EV charging cable easily costs 250 to 350 Swiss francs, and you can't just extend them like that either, and I wouldn't even think of using a 22 Swiss franc extension cable, it's far too dangerous. It's best to look through the vehicle's manual, which specifies which cables may be used for charging.

This is an extension cord with a German plug. However, the European standard is well respected.