The Stripe add-on needs to be installed and activated to see the features mentioned in this this documentation.
Note: Make sure your website meets Stripe security standards before use
Stripe has specific HTTPS and TLS security standards that your website must meet to be able to use their service to collect payments. If your website does not meet these security standards, you will not be able to communicate payment information to the Stripe service. Please see their documentation for details. If you have questions about your WordPress website meeting these standards, please contact your hosting provider.
Connecting Ninja Forms to Stripe
The first step to using Stripe with Ninja Forms is getting your API credentials. This will allow your forms to communicate with Stripe and is a required first step before payments can be collected.
You can find your API credentials in your Stripe dashboard.
Enter these keys into your dashboard under Ninja Forms > Settings > Stripe. Be sure to Save Settings after.

Stripe Payment Template
The Product and Total fields have been deprecated since version 3.4.6 of the Ninja Forms core plugin https://wordpress.org/plugins/ninja-forms/#developers This was done due to them causing several bugs and not functioning with currencies that use a format different than the American format of commas and decimal points.
Going forward, you will need to set up a calculation instead. https://ninjaforms.com/docs/calculations/
Setting Up a Stripe action
Before setting up your form, be certain that you have set up your API credentials as described in the section above.
First, open your payment form and click on the Emails and Actions tab at the top of the form builder.
Next, click the blue circle/+ icon in the bottom right of the screen to open the list of available actions.

Choose the Stripe action from the list of available actions.

With the action added to your form, click to open it. If you selected the Collect Payment action, you’ll need to set the PAYMENT GATEWAYS setting to Stripe. If you selected the Stripe action, this is already set for you.

You now need to set the total that will be sent to Stripe in the GET TOTAL FROM setting. This can be one of four options:
What each of those mean and how their configuration options are covered in the sections below.
In the Customer Email Address setting, a merge tag for the email field of your form can be entered to pass into Stripe associated with this charge. This can be used within Stripe to send a receipt.
Sending additional details to Stripe with the charge
You can send Shipping Address information to Stripe with the payment by turning on the Show Shipping Address toggle under the Advanced Settings of the Collect Payment Action.
To change the Product name that is sent to Stripe, you can go to the Advanced settings and you will see the field, Product Name
If you want to include a description of the product(s) into Stripe or other details when the charge is processed, that option can be found under the Advanced settings of the Stripe action.

You can send an image to Stripe for the product purchased by filling out the Product Image URL field. Note: This URL must be a valid URL for the image you want to use.
Additional metadata can also be sent to Stripe by setting up key-value pairs in the section provided under the Advanced Settings of the Stripe Action.
To find out more information about Stripe Metadata, you will need to reference the Stripe API documentation.
Enabling Testing Mode
To enable testing for your form, toggle on (green) the Test Mode setting. This setting is found under the Advanced settings of the Stripe action.

With the appropriate Test API credentials entered as described in the Connecting Ninja Forms to Stripe section above, submitting the form in this mode will allow you to test the form with Stripe. This must be toggled off to accept live payments.
Stripe also provides a list of test credit cards that you can use while testing:
https://stripe.com/docs/testing
Test Card Example:
4242424242424242
Processing of the Stripe Payment on Form Submission
As of version 3.1 of the Stripe add-on, the plugin has been updated to meet the Strong Customer Authentication (SCA) rules required for payments from EU users. This is done through the Stripe add-on by using Stripe’s 3D Secure Card Payment
When a user makes a submission on the form that has a Stripe Collect Payment Action activated on it, the user will be forwarded to Stripe’s site (https://checkout.stripe.com) to make a secure payment.
Once the payment is made, the user will be sent back to your site to complete the payment token in Ninja Forms. The rest of the form actions will then process.
Stripe Merge Tags
{stripe:last4}
This returns the last 4 digits of the Credit Card from the Stripe payment. The data from this merge tag is not populated until after the payment is made.
{stripe:cardtype}
This returns the Credit Card type from the Stripe payment. The data from this merge tag is not populated until after the payment is made
{stripe:customerID}
This returns the Customer ID from the Stripe payment. The data from this merge tag is not populated until after the payment is made.
{stripe:chargeID}
This returns the Charge ID from the Stripe payment. The data from this merge tag is not populated until after the payment is made.











