As long as the oil is changed at the correct interval, with oil meeting the proper specifications and a good oil filter, the warranty requirements are met. The Toyota dealership or any quality service shop can perform the service for you.
It may even be in your best interest to use a shop other than the dealership. Warranty work pays less than customer paid repair. It is possible a dealership may be less likely to point out repair, that could be under warranty and is close to the end of the warranty period. Certainly not every dealership would do this, but a second set of eyes may not be a bad idea, in my opinion.