How can I print a completed form?

If your aim is to print a form with the user's submitted data showing, you have 2 options based on what your actual requirement is. Since you haven't given us more info, I'll just list them both so we can cover everything:

1. For future submissions - Utilizing the PRINT option on the SUBMIT button and the EDIT link for Email Notifications

The general workflow will be as follows:

   a. You setup your form to have the PRINT button (here's how)

   b. You will modify your email notification template to include an EDIT link

   c. Once you receive a submission via email, you will click the EDIT link > it will show your user's submission data > and then all that's left is to click the PRINT button you added

   d. Optionally, you can also use the built-in print function of the browser (CTRL+P)

2. For previous submissions - Utilizing the Submissions Panel to print them

   a. You setup your form to have the PRINT button too

   b. Go to your SUBMISSIONS page

   c. Click the submission you want to print out. This will open the form in the edit mode so all of your data should be clearly shown to you.

   d. Then click the PRINT button on your form

For a more detailed guide, please have a look at this page: How-to-Print-the-Form-with-the-Users-Data 

On the other hand, if all you wanted to do is to print your form, then you can either use the built-in print function of your browser (CTRL+P), or use the Print Button

Let us know if you have further questions.