2. Find the personalized signature field, move the cursor over the personalized signature (be careful not to click), and an "Edit" button will appear.
3. Click "Edit" button to enter the interface of editing personalized signature.
4. In the interface of editing personalized signature, click the "Settings" button above personalized signature.
5. In the settings, find the "View Permission" option and set it to "Visible only to yourself".
6. After setting, click the "Save" button in the upper right corner to save the setting.