There is no one-size-fits-all answer to this question, as the value of copyediting certification depends on a variety of factors, including your career goals, your previous experience, and the type of certification you choose.
That said, many copyeditors find that certification can help them to improve their skills, demonstrate their commitment to their profession, and make themselves more attractive to potential employers.
There are a number of different copyediting certification programs available, so it's important to do your research to find one that meets your needs. You can learn more about some of the options here:
https://www.copyediting.com/which-copyediting-certification-is-right-for-you/
https://www.copyeditors.org/store/p/12/cer-tification-training-program
https://www.academyofedited.com/our-training/certification/