Each Club in the group of 5 Clubs is asked for one resource at a time (between Earth, Water and Sun) and in the same order, for example the Sun could be asked first, then the Water, then the Earth and the exact same sequence will be request to all clubs in the same group.

The number of resources required from each Club in the group (for example in the image 80 Suns are required) can vary because it is proportional to the number of members of your club.

To donate the resource, each club member will simply have to click on the button of the requested resource, in this example the Sun.

If you do not have the requested resource available, you can donate a joker   

In your Club panel you will be able to see how many resources each member of your Club has donated, it is the number under the word Challenge (indicated by the red arrow in the following image.