You can allow anonymous donations or not on a per-campaign basis. Donations where the donor chose to be anonymous are clearly marked and that choice is respected by display elements.
When a donor chooses to make their donation anonymous, meaning that they would not like the organization to acknowledge it publicly, Fundraise Up will automatically redact their donor information from any elements that display info like Social Proof, Recent Donations, or more, and will mark the donation as anonymous for data handling via external integrations.
Based on that marker, we recommend having filtering for any downstream attribution reporting that specifically excludes donations marked as anonymous
This is different than an anonymized payment, where the payee's info is not available to the organization. For example, among other providers, Venmo does not allow anonymous payments.
Anonymity in Fundraise Up is treated as a decision between the donor and the organization, on the presumption that the org will still have donor information for anonymous donations, and will simply choose not to display that publicly for anonymous donations on any forms or elements.