The Supreme Court said Monday that it would not take up the appeal of Michelle Carter, the Massachusetts woman serving a 15-month sentence for coaxing her boyfriend to kill himself.

Carter, 22, who began serving her sentence in February, was convicted of involuntary manslaughter in 2017 in the death of her then-boyfriend, Conrad Roy III, who was 18 at the time.

“You can’t think about it,” Carter texted Roy in 2014 before he killed himself with carbon monoxide in his truck in the parking lot of a Farhaven Kmart. “You just have to do it. You said you were gonna do it.”

The texts were found on Conrad’s mobile phone after his death, leading to Carter’s arrest.

Carter appealed the conviction in Massachusetts but was jailed and began serving her sentence after the state’s highest court upheld her conviction in February.

Carter’s lawyers then appealed to the Supreme Court, claiming her First Amendment rights were violated because she was found guilty based on her own words — or texts.

The justices on Monday declined to take up the case.

With Post wires