docs: update nextJs theming apply description

content/start/getting-started/index-en-US.md

@@ -151,5 +151,8 @@ Introduce the full amount of semi css in `global.css`. Currently, on-demand impo
 
 **Using theme in nextjs**
 
-Please refer to [this issue](https://github.com/DouyinFE/semi-design/issues/565)
-
+You need to replace the path of the import statement in Step3, and replace the default theme CSS product with the CSS product in your customized theme package, for example, the theme package is `@semi-bot/semi-theme-nyx-c`
+```css
+/* styles/globals.css */
+@import '~@semi-bot/semi-theme-nyx-c/semi.min.css'';
+```

content/start/getting-started/index.md

@@ -85,9 +85,12 @@ module.exports = semi({
 @import '~@douyinfe/semi-ui/dist/css/semi.min.css';
 ```
 
-**在 nextjs 中使用主题包**
-
-请查阅 [此 issue](https://github.com/DouyinFE/semi-design/issues/565) 中的方法
+**如何在 nextjs 中使用主题包**  
+你需要更换 Step3 中 import 语句的路径，将默认主题 CSS 产物更换为你定制的主题包中的 CSS 产物，例如主题包为 `@semi-bot/semi-theme-nyx-c`
+```css
+/* styles/globals.css */
+@import '~@semi-bot/semi-theme-nyx-c/semi.min.css'';
+```
 
 ## 4、UMD 方式使用组件