ConvertKit allows you to add custom fields to contacts. These are things like a birthday, or phone number. We can use a custom field for our Hello Audio subscribe links to be sent to individual listeners.

The tools you'll need:

Click "Landing Pages & Forms" at the top. Then "Create New".

Choose "Form" and pick any template to start customizing. NOTE: This form/landing page won't be seen by anyone. It's a completely internal tool, so don't worry about exact language or design.

Add a field with the + icon under the email address box of the form. On the right, Save as "Custom Field" and type something descriptive like Subscribe Link in the "Custom field" box. Then click "Create New Custom Field".

Click Settings, Incentive. Uncheck "Send incentive email" to prevent the double opt-in email being sent. This assumes the email collection at the time of purchases/signup for the feed meets your requirements. If you leave this box checked, it will send an "Important: confirm your subscription" email when the Zap fires.

Rename the form at the top-left so you can identify it in Zapier.

When Zapier adds someone to the form above, we'll want to send an email from ConvertKit. This is done using an Automation and a Sequence.

Click "Automations" at the top, then "New Automation".

Select "Create Automation", then "Joins a Form" and choose the form you created above. Then "Add Event".

Click the + icon below the form and choose "Email sequence" under "Action". Create a name for the sequence, then click "Create new sequence" then "Add Action".

Click on your sequence to edit the email. Customize the email to your liking.

When you're ready to input the subscribe link, type ##{{ subscriber.subscribe_link }} if your Custom Field above was "Subscribe Link". If it was something else, type it in lower case text with _ replacing spaces. It must have two curly brackets with spaces between them and the text. The text starts with "subscriber." and ends with your custom field.

TIP: To get the formatting right, click the + icon on the left and scroll to "Personalization". Click "+ Add to email" under "Subscriber first name", then replace "first_name" with your custom field.

You can hyperlink text or images by highlighting text, then clicking the link icon and entering in the custom field.

It should look like the image below, and appears in the inbox as follows.

Edit the time for "Send this email" to 0 days, which changes it to "Immediately".

Finally, click "Publish".

Here's the outline of the Zap you're about to create:

Create a new Zap and pick your trigger that starts the automation. This could be a purchase or subscription or whatever you'd like. It needs to contain at least the contact's email address.

The Action step after the trigger is going to be Hello Audio. Choose "Add Listener" for the Action Event and then click your account. If you've never connected Hello Audio to Zapier, you can do so now.

Choose the feed you'd like, and select the email address that was passed from the trigger. Select "False" for Send Email, that way you can send it from your own ConvertKit account.

Click + to add another step in the Zap. This is your ConvertKit connection.

Choose "Add Subscriber to Form" for the Action Event. Select your CK account and continue. If you haven't connected CK and Zapier yet, here are their instructions.

Pick the form that you created above and add their email address from the trigger, as well as their name if you'd like.

Be sure to select "Yes" for "Optin to sequence". (It should be selected by default.) This is what sends the email you created above.

Select the "Subscribe Page Link" from the Hello Audio step to fill in the "Subscribe Link" of the custom field (or whatever you named your custom field). Click Continue.

Test your action, and turn on the Zap. Done!

In ConvertKit, you can confirm all is working by checking the test contact you used for the Zap. They should have a Hello Audio subscribe page URL in their custom field as shown below.

Test the entire process from start to finish by triggering the Zap with whatever you've chosen (a purchase, an opt-in, etc), and ensure the email is delivered as expected with a working subscribe link.