How did Lin Beixing cross back?

Because Zhang Wansen's "Jumping off the Lighthouse" and his "I Like You", Lin Beixing can cross back.

This is the hostess of the twinkling stars. "Twinkle, twinkle, bright stars" is a fantasy suspense love drama starring karina and Qu, Caesar, Jinna, Luo Mingming, Jiang Yunlin and Lu Daxu. The play tells the story that Lin Beixing accidentally deleted the text messages in her old mobile phone, went back to the past and got to know Zhang Wansen, a former stranger, and started a wonderful journey to save time and space.

Lin Beixing, a 30-year-old senior girl, lost her life and work because her boyfriend Yu Zhan broke the contract and missed her dream love hall. I don't know whether it was fate or the old man's joke in the time machine, but Lin Beixing actually returned to the age of eighteen. Senior three is a nightmare, but Lin Beixing plans to take the college entrance examination again, get rid of Yu Zhan and live for herself again. However, Lin Beixing's dream was frequently broken by a boy named Zhang Wansen.