If you lose the original file, you will not be able to prove ownership anymore, even if you still have the certificate and the transaction ID.
This is because:
The certificate is tied to the SHA-256 fingerprint (hash) of your file, not the file itself.
Blockchain records cannot be reversed: it is impossible to reconstruct or recover the original file from its hash.
Without the original file, you cannot recompute the hash and therefore cannot prove that the certificate belongs to that specific content.
For this reason, we strongly recommend that you store your original files in secure and redundant locations, such as:
Encrypted cloud storage,
External hard drives or USB keys,
Or a trusted archival service.
Unlike the certificate (which can in some cases can be regenerated) the original file cannot be recovered or re-linked to your certificate if lost.
Conclusion: keep your file safe. The blockchain record proves that a file existed and was registered, but only if you still have that exact file to present.