Usually, you provide master recording information to a digital distribution service, such as CD Baby or Distrokid. These services can help make your recordings available for streaming and purchase.
As a publisher, Songtrust administers compositions. This is separate from recordings.
If you make music, you own two types of copyright, the master recording and the composition. As your publisher, Songtrust collects royalties from the composition side. Your distributor (DistroKid, CDBaby, etc...) or label collects royalties on the recording side.