Where did this coin come from?

Paste any mint. If an identity here signed a record naming it, the signature is re-checked in front of you against that identity's root, and the record it covers is shown in full. If none did, this says so, which is the expected answer for a coin launched anywhere else.

Either way the chain is read and its answer is printed with the slot it came from. A mint is a fact about Solana; an attestation is a fact about who signed, and each one of the 256 keys an identity holds signs once.