Yes, you can change a tip on Instacart. With the app, users are able to modify their gratuity either while
placing an order or after delivery has been completed. If you would like to increase your tip amount, you have
up to 14 days after the delivery is complete to do so.
However, recently Instacart modified their controversial policies. If you decide that you would like to reduce or remove
your tip, then you have up to 2 hours after the delivery is completed to adjust it. This flexibility allows customers
to make changes based on the level of service they experienced and their opinion of it.