A dialog for saving the transition opens. Enter a suitable title here.
The file name is generated automatically, but can also be changed. The file extension .atr must be preserved.

Category name: With the small black selection triangle you can choose from the existing categories. If no category name is selected, the transition will be placed under the category"Own transitions". Alternatively, you can enter your own category name.

Show as child element of transition: The custom transition is displayed as a child item in the selected transition category.

Click OK to save the transition.

You can now find the transition in Toolbox tabs and in the properties in the selection list for the Fade-ins and Fade-outs.