Okla. Stat. tit. 21 § 142A-5
The district attorney's office shall provide all victims, regardless of whether the crime victim makes a specific request, with an official request for restitution form to be completed and signed by the crime victim, and to include all invoices, bills, receipts, and other evidence of injury, loss of earnings and out-of-pocket loss. The crime victim shall provide all documentation and evidence of compensation or reimbursement from insurance companies or agencies of this state, any other state, or the federal government received as a direct result of the crime for injury, loss of earnings or out-of-pocket loss. The unexcused failure or refusal of the crime victim to provide all or part of the requisite information prior to the sentencing, unless disclosure is deferred by the court, shall constitute a waiver of any grounds to appeal or seek future amendment or alteration of the restitution order predicated on the undisclosed available information.
Okla. Stat. tit. 21, § 142A-5