I did everything mentioned above still i am not able to get the header and footer and also the print button which automatically appears dosent seems to appear at all. I also noticed that if i download the pdf preview in settings it doesnt come with the header and footer.  It shows the header and footer only in the preview and disspappers after downloading ! 

Use 'web' module as depends in manifest file and restart your server

Hello Guhan,

I am assuming that you have added needed dependencies, if you not that you need to add 'depends': ['web'], in manifest.py

Generally header and footer are being added with such code

You can also use Odoo Studio for to implement this changes. Simply follow below steps 

1. Click on Studio.
2. Click on Reports.
3. Select New.
4. Choose External.
5. You will automatically get pre-defined option for header and footer. 

I hope this will help you !

Thanks,
Vimal Rughani (Founder and CTO)
Himanjali Intelligent Automation Pvt Ltd
Contact: +91- 972-606-7737
Email: hello@himanjali.com 
Newsletter: The Odoo Scoop
Website: www.himanjali.co

Hi,

Does your module depend on the web module? web.external_layout is part of the web module. If your module doesn't depend on it, adding a dependency might be necessary. 

Hope it Helps!