About 2003 Model Pejo 307 HANDBRAKE ON warning.

Hello friends, 1 month ago I joined you by buying a 2003 model XS 307. First of all, I did all the heavy maintenance of my vehicle and brought it to working position like clockwork. I had already deducted the heavy maintenance costs :) Today at work, I wanted to pull the handbrake around 18.30 and have a little chat with my friend in the car. I got a HANDBRAKE ON warning on the trip computer. I saw a video on youtube, a foreigner cable etc. it seems like he solved the problem by making a change.. Can you, dear 307 users, enlighten me? I live in Ankara.