Visit the official UPSC website: https://www.upsc.gov.in
Open the “Examinations” section
Select the relevant UPSC Exam 2021 notification
Read the official notification carefully
Check eligibility criteria, age limit, and educational qualifications
Register on the UPSC Online Application portal
Fill in the required personal, academic, and contact details
Upload the required documents, photograph, and signature
Pay the application fee, if applicable
Review all details before final submission
Submit the application form online
Download and save the submitted application form
Take a printout of the application form for future reference