There is currently no way to do this natively with RevenueCat. However, there are a couple of ways that you could achieve this with RevenueCat and Firebase together. They all revolve around handling purchase events. The RevenueCat Firebase integration writes events to the selected event collection, so you would create a listener that listens to any new events in that collection, and then handle them.
If you receive an INITIAL_PURCHASE event for one of the consumable products that you have set up, you unlock the entitlement. There are a number of ways to do this, but my recommendation would be to make a REST API call to the RevenueCat Grant a Promotional Entitlement (revenuecat.com) endpoint. You will need to generate a secret API key to make this REST API call, and you can create a one-day promotional entitlement for the affected customer using this API.
Let me know if this helps or you have any questions!