Order Printer Pro: Invoice App

How can I incorporate digital signature on Invoice. As per rule Invoice to be prepared at our office and to be signed by official (Manually or Digitally)
If not done then it is violation of GST rules.

Absolutely awesome app and support!! Support was able to help me within minutes of setting up the pdf link with my order confirmation email, and stayed online till I was successfully able to get it done. thank you so much.

easy to set up and works straight off the bat..
the customer service is also fantastic. got on a chat and got answers and solutions straight away.

Very good support ! thanks to the team, i had a little issue and they directly renspoded to solve my thing :)

AWESOME. Great App, Easy coding into the already awesome template. I encourage all to do this - saves you paper and the environment by going paperless.
Perfect solution, thanks guys!

I use this app to help me print professional looking itemized receipt. I once emailed them about displaying a customer's name with all the correct capitalization because it wasn't showing up how I typed it and they helped immediately even during the Christmas time after I said this is no rush. Very nice people to deal with. ------------------------------- Also got help with customizing receipts

Just started using the app and it seems fairly straight forward, plus removes a lot of manual work.

Template was missing our VAT number and I was unsure how to add this within the HTML template. Valeria was so patient and clearly explained step-by-step how to enter this information and create the right template.

Fabulous support! Thanks so much :-)

Very good app, easy to use and nice templates.
The support is great, very kind and helpful!

I have used this to make my invoices for years with a template I created. Excellent look and functionality. Recently when Shopify introduced "Shopify Taxes", I had 5 lines of local taxes on one invoice (California)!
After emailing them they got back to me almost immediately, and wrote new code for my template that combines all taxes to one line. Now the invoice looks nice and is not confusing.
Amazing customer service, a really nice looking template, plus great support.

Everything about this app is incredible. The support is amazing and it is just an all around top notch app.