The Twingle Campaign campaign type does, unlike the other campaign types (Twingle Project & Twingle Event), not represent an entity on the Twingle side.
The Twingle Campaign is can be used to track the origin of a donation. In order to achieve this, it takes the URL of
it's Twingle Project parent campaign and adds a cid parameter to its end that will be sent to Twingle and back. With
the cid coming back from Twingle via API call to TwingleDonation.submit (provided by the Twingle API extension)
the donation can get assigned to the originally Twingle Campaign.
Attention: The Twingle Campaign must always be the child (or grandchild) of a Twingle Project.
You can use the Twingle Campaign url for example for newsletters or social media posts. The url will lead the users to
the Twingle donation form of the parent Twingle Project but thanks to the cid, the donation will be assigned to
the Twingle Campaign.