The prepositional phrase present in the sentence is "in the morning." It refers to time as it is a period during the day.
The preposition included is "in" and the object of the preposition is "morning," which is modified by the definite article "the".
Explanation: prepositions are function words which relate to time, place, agents, etc.
Objects are what it is 'talked' about by prepositions in a prepositional phrase.