Make sure you have Java 21+ and run Spigot 1.21 (Or lower). For spigot versions < 1.21, use older versions of SimpleAdvertising. This version is only compatible with 1.21
Did you get the dependencies? If you want to only allow double jumping in certain regions, you need worldguard
The plugin is working "out of the box", but it is recommended to tweak the config to your taste
Now, just fire up your server, or load the plugin, and everything should be working just fine
If you have any problems, don't hesitate to contact me, and if you really love the plugin, consider leaving a nice review.