Import contributions without name
By default, CiviCRM requires at least one of email, first name, or last name. You can change this at Contacts > Find and Merge Duplicate Contacts, creating a new rule and setting it for usage when unsupervised, or, more appropriately, by selecting it as the Dedupe Rule when importing at Contacts > Import Contacts. Beware of setting the rule to identify duplicates too loosely, as you will end up with lots of duplicates in your database. This is a complicated, tricky area...good luck.