diff --git a/book/features/adding_HTML_elements.md b/book/features/adding_HTML_elements.md
index af778c8..78a6cf0 100644
--- a/book/features/adding_HTML_elements.md
+++ b/book/features/adding_HTML_elements.md
@@ -32,7 +32,7 @@ Let's take a closer look at the source. Since this project uses a local file str
  - Finally, the string `"element_render_box.html"` selects the HTML file we want to embed. We are now in `book/_static/element_render_box.html`.
 
 ## Viewing result at local build
-To view the final result locally, it's required to setup a {ref}local Python webserver <setup-local-server>`.
+To view the final result locally, it's required to setup a {ref}`local Python webserver <setup-local-server>`.
 
 ## HTML code for the 3D render element
 
@@ -196,4 +196,4 @@ To conclude, I provide the HTML/JavaScript code for the 3D render element above.
 </html>
 
 
-```
\ No newline at end of file
+```