diff --git a/Readme.md b/Readme.md
index 20f0402..9f98c25 100644
--- a/Readme.md
+++ b/Readme.md
@@ -37,9 +37,13 @@ In KiCad's PCB editor, go to `Preferences → Preferences → PCB Editor → Gri
 - Click **Plot** and **Close**.  
     <img src="images/KiCad_Plot.png" alt="KiCad Plot" width="500"/>
 
-### 4. Create the `Dummy.pm4n` file
+### 4. Install `CHITUBOX Basic`
 
-Open **CHITUBOX Basic** slicer (or any other slicer that works for your resin printer), select printer **Anycubic Photon Mono 4**, slice any tiny STL (e.g.: 1×1×0.05 mm box), and save as `Dummy.pm4n`.
+Follow the [offical installatin guide for Ubuntu](https://docs.chitubox.com/en-US/chitubox-basic/latest/installation#ubuntu)
+
+### 5. Create the `Dummy.pm4n` file
+
+Open `CHITUBOX Basic` slicer (or any other slicer that works for your resin printer), select printer **Anycubic Photon Mono 4**, slice any tiny STL (e.g.: 1×1×0.05 mm box), and save as `Dummy.pm4n`.
 
 This file is reused for every job — it carries the correct LCD resolution metadata.