TXT records, or text records, define text information about sources outside of a domain. Common use cases for TXT records include creating email security records (DKIM and SPF records) and providing additional information about a domain.
DigitalOcean uses TXT records to associate a string of text with a hostname. These are primarily used to verify that you own a domain.
In App Platform, TXT records are the records for issuing certificates when adding a custom domain.