Java / Minecraft | Forge Mod Export Error?

I program a mod for the first time, or change one. Now I wanted to export it and then errors occurred because it doesn't know "diamond operator" and "lambda expressions". The mod runs on -source 1.6, would that be JDK 6? May be. At least I now need -source 8. How can I use -source 8 so that the errors both disappear?

The Diamand operator was introduced in Java 7 and lambda expressions in Java 8, so you need Java 8. You download it (eg https://adoptopenjdk.net/) and then select the path to the JDK8 in the compiler settings in the compiler settings.

Thanks, everything worked.