Adding cookies to an existing site. (Asp.Net)

there is an active site available. I have added a cookie to this site. When the site opens, a button like accept appears and I can accept and close it. My question is how can I set the duration of this? Where are these cookie files? I see Js Document.cookie videos. They write to Script.js files. Where do they copy this file? I would be very happy if you answer.

The site is currently active.

I copied the ready-made script code from the site called Mosono and copied it to my default.aspx page. So what should I do next? How do I set the duration of this cookie? Where is this data stored? I couldn’t find it in AppData Local folder for Chrome. Or rather, is it a cookie? I am providing the link for you to view the site. I would be glad if you help.

http://www.kamerholding.com.tr