In response data, you will see some image links without the host reference at the beginning.
Ex : /20210803_287/1627948709488iqURm_JPEG/5OnceAHero_mobile_thumbnail.jpg?type=q70

You need to manually prepend “https://webtoon-phinf.pstatic.net” to the beginning of every links.
Ex : https://webtoon-phinf.pstatic.net/20210803_287/1627948709488iqURm_JPEG/5OnceAHero_mobile_thumbnail.jpg?type=q70

It is not final yet. You cannot still access the link directly by web browser. You have to make GET method request with the following in request headers :
User-Agent:Mozilla/5.0 (Linux; Android 8.1.0; Mi MIX 2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.125 Mobile Safari/537.36
Referer:http://m.webtoons.com/