Many asylum applicants cannot obtain every document they would like from their home country. A missing document does not mean you should invent, alter, or purchase false evidence.
Record what is missing
Create a missing-evidence log with the document, the fact it would support, who might have it, attempts made to obtain it, dates of those attempts, responses received, and any safety or practical reason further attempts are not reasonable.
Save emails, messages, delivery failures, agency responses, or other proof of attempts when available.
Look for legitimate alternatives
Depending on the fact, other evidence might include witness statements, photographs, messages, medical bills, identity records, travel records, organizational records, or reliable country information.
Alternative evidence should be genuine and should actually support the fact at issue.
Safety comes first
Do not put relatives or other people at risk merely to obtain a document. If contacting someone or an institution could be dangerous, record that concern and discuss it with a qualified attorney or accredited representative.
Official sources
A representative can help assess whether missing corroboration needs an explanation or whether another source can reasonably support the fact.