"upon such a request" is a correct and usable phrase in written English.
You can use it in a variety of different contexts. For example: "I would be more than happy to assist you upon such a request."
Upon receiving such a request, the State shall negotiate with the Indian tribe in good faith to enter into such a compact.
Upon receipt of such a request, OPM will identify and "flag" a debtor's account in anticipation of the time when the debtor requests, or becomes eligible to receive, payments from the Fund.
Upon receipt of such a request, the Regional Administrator, with the concurrence of the Chief Administrative Law Judge, shall publish notice of a hearing to be held not less than 30 days following the date of such publication where he determines that there are factual issues concerning the existence of the alleged discrimination or its relationship to an effluent limitation or order under the Act.
Such a request is highly unusual.
Upon such request, the person maintaining the records must furnish the records, the equipment, and if necessary, knowledgeable personnel for locating, reading, and reproducing any record that is required to be maintained in accordance with this section.
Upon such request, the Certificate Authority issues certificates only to trusted nodes and thus enables secure data transmission.
Where workers are separated, employers are required to furnish the agency promptly, either upon agency request or upon such separation, a notice describing the reasons for and the circumstances of the separation and any additional information which might affect a claimant's right to benefits.
When a journal's instructions for authors mentioned that such a form was available upon request, the form was requested.
Upon review of an individual's personal record, that individual may submit a request to amend such record.
They can download software that generates such numbers upon request or upon detecting that a cardholder is at the checkout page of an online retailer.
