There is a big picture in this link https://www.sunday-webry.com/viewer.php?chapter_id=91141, the url of which can be found with inspector, looks like blob:https://www.sunday-webry.com/1dfc33a7-cb4c-44f9-8642-df87bfc91fd5. (blob links are only available in individual browser instances)
However, this blob link is unaccessible. The browser complains:
Your file couldn’t be accessed
It may have been moved, edited or deleted.
ERR_FILE_NOT_FOUND
blob link is sometimes accessible with link, see the blob image links found in https://viewer.ganganonline.com/manga/?chapterId=39373.
There should be some way to access the first blob image by link directly like the second one - but how to achieve that?