Different domain with the same content

Well, I am looking for a plugin or solution for my situation. I need 2 domains for the same content because my main domain is block by Chinese Wechat Built-in browser by the reason of strange Chinese white list rules. By the way Wechat is a decent mobile app with more than 1 billion user. So，I need another domain with the same content, https://www.domain.mobi, and for the SEO issue of same content. It is better use <link rel=”canonical” href=”https://blog.example.com/dresses/green-dresses-are-awesome&#8221; /> on the head part, or no-index as solution.