How to handle requests that will be picked up by a person and responded to within 5 minutes

I'm currently designing a voucher/discount journey.Due to system constraints, this is the scenarioUser needs to request a voucher.The request then goes to a crm that is managed by individuals.Individuals will respond with voucher number within 5 minutes of the request coming into the CRM.Once the voucher/discount is sent to the user, they only have 2 minutes within which to use it on the platform. If they don't it will expire and they need to request another voucher/discount.I've thought of in-app notifications to let the user know that the voucher is ready, but since the voucher is only valid for 2 minutes, I'm not sure if there's a better way?