By pressing Add Transformer navigates you to a new pop up window as shown in the example below where you fill out the new transformers label.
Transformer creation fields
|The label of the transformer.|
If you did all the steps correctly the Transformer should be created in the Settings → Transformers and shown as in an example. After creation you can Edit the transformer, you can Edit the code of the transformer or Delete it from the list.
If you want to start writing down your transformers code then press on Code edit action icon button and a new pop up window appears where you can write down your code as shown in the example.