This isn’t really a question. It’s a blurp of your novel. It’s the main point of the novel, showcasing the character and the main problem he/she has to solve throughout the novel. Or, it can showcase the current situation of your main character. I mostly use the latter for a romance novel.
For instance: My story titled Beautiful Mistake, from The Girl in Suits series. A one night stand turned whirlwind romantic catastrophe between a marketing assistant and an eligible bachelor, who was also her boss.
In this blurp, I gave away who are the characters ( a marketing assistant and eligible bachelor) and pointed out a plot that pushed the story to progress (a one night stand). Lastly, I described the theme of the novel ( a whirlwind romantic catastrophe). This gives the reader a hint of what to expect.