2012 A7 Burning Oil
 

My 2012 A7 with 162000 kms now getting add 1 litre oil every 500kms of driving.
No oil stains on driveway.
Only 500 kms and having to add 1L oil is crazy.
Does anyone have an answer or fix for this or what I should look for ? No error codes coming up. Any help is appreciated. Thanks