Rokyan

Hi! I followed this tutoriel to create my own planet, but I'm stuck at step 7. It is said that I have to open the Kittopia GUI with Ctrl P. Once there, I have to select my planet in "Planet selection". But it is not there I can select all the stock planets (Kerbin, Moho etc) but my planet does not appear in the list. Could someone help me please? ( I'm sorry if my english isn't perfect, I'm french )