Hi Abdul!

As per the eligibility criteria to write the exam, candidate must attain the age of 21 and should not exceed the age of 32 years. For UPSC exam, age will be counted from July 1 of the notification year. As you mentioned your date of birth is 3rd August 2002, you will be of 21 years in 2023, so yes you can write UPSC 2023 exam. To know more, visit here:

https://competition.careers360.com/articles/upsc-ias

Thankyou!