Covering your own songs always works; third-party songs need the creator's remix permission. To use your own track, upload it to your free Suno account, make it public, then paste its song link.
Style / tags
New tracks
API </>
API key (used in the snippets below)
Budget:
Copy it now — it won't be shown again:
POST — same call the form above makes. The web UI is just a wrapper around this API.