engine starter problems

Hello,

Just so that we cover the basics, have you tried to jump start the car?
If you are able to jump start the vehicle and it runs normal, then you likely have a bad battery.

https://www.2carpros.com/articles/how-to-jump-start-car-battery-using-jumper-cables

If you are unable to jump start it and the starter only clicks and does not crank the engine, then the starter is likely the issue.

Here is a helpful guide:

https://www.2carpros.com/articles/starter-not-working-repair

Depending on the engine code of this A3 there are three different starter and replacement procedures. I have attached all three for your reference.

Please let me know of any questions.
Thank you.