Explanation

I have been waiting for 3 hours

میں 3 گھنٹے سے انتظار کر رہا ہوں۔

The Tense of the sentence is Present Perfect Continuous tense because "have been waiting" is given in the sentence.

Have been in the form used with any other subject (including the pronouns I, we, and they)

ND18-9-2023