First you need to decide which payment processor you want to use.
We integrate with WePay, PayPal and Braintree. Their fees are comparable. WePay is an easier and quicker setup, but Braintree is a more "complete" integration with the ability for your payers to save their payment information in their vault. Both solutions require you to create an account on their system. For security, we think less parties involved in the credit card process is easier and safer. That's why we seamlessly pass through the credit card info to these merchants and they charge the card. They then tell Duplie the results and we store the additional user information and handle the confirmations/emails.
Ok, so back to setting up your merchant. Login to your site and go to Site and then click Payments. There you should see the options for WePay, Braintree and PayPal. To setup WePay, click on the WePay setup button which will take you through the WePay creation process and link your account. You should receive emails from WePay to verify your information. For Braintree, visit their site (https://www.braintreepayments.com) and create an account. Once you have signed up, you will need to create an API authorization. It's currently found under Account >> My User >> View Authorizations. There you will 'Create New API Key'. This is the information you will need to enter into your Duplie Braintree account which will authorize Duplie to send payments to your account. You will need to enter your Merchant ID, Public Key and Private Key.
Once the merchant information is linked, you should be able to create Fundraisers, Registration Forms, or Products to collect money online. The funds collected will be sent to your linked merchant payment processor which will be linked to your bank account. The funds will then be deposited to your account on a batch basis as they are collected within Duplie.