2006' Opel Astra

I am selling a car in good condition, there may be minor scratches in some places. The yellow engine check light came on several times (definitely not the spark plugs, as I was just replacing them). The horn doesn't work.
The oils and filters were changed in March, I also did the air conditioning and replaced the rear beam bushings. The LPG decision is valid until 30/11/24, the insurance is valid until 04/12/24.
Technical inspection until 27/12/24
Please contact me.