You can insert different watermarks into various pages of your document by using text boxes.

1. Insert a text box anywhere in your document from the Insert pane on the left panel.

2. Add the desired text, format it as needed, and rotate it with the cursor if you want the watermark to be diagonal.

3. In the Text Box options pane, set the wrap type to Behind Text. The text box will now appear like a watermark in the specific section of the document.
   
   
   

 
If you want to place the textbox/watermark in the header,

1. Make sure your document is divided into appropriate sections.

2. To add sections,

1. Place the cursor before the page after which page orientation has to be changed.

2. Insert Tab → Breaks → Section break → Next Page , to insert a section break.

3. Now, in the left panel, uncheck the option Link to previous section.
   
   
   
   
   
   
   

   If you skip this step, the same text box will appear on all the pages of the document.

4. Now insert a text box from the Insert pane on the left panel.

5. Add the desired text, format it as needed.

6. In the Text Box options pane, set the wrap type to Behind Text. The text box will now appear like a watermark in the header of the document.