See if you have downloaded your application confirmation page then you have to search it out from your download section of your device. If you don't find it in the device then you can search it out in the recycle bin. Now if you don't have it then you need to contact your KCET helpdesk for the same and get it discussed. They only can give you some hint.

For the contact details visit:

Karnataka Examinations Authority,
Sampige Road, 18th Cross,
Malleshwaram, Bangalore - 560012.
Phone No: 080 - 23460460
Website: http://kea.kar.nic.in
E Mail: keauthority-ka@nic.in

For the official website visit the link below:

https://cetonline.karnataka.gov.in/kea/contact_Us

To know more about KCET visit the link below:

https://www.careers360.com/exams/kcet

I hope this answer helps. All the very best for your future endeavors!