Steps:

Create a user specifically for establishing the Procurify and QuickBooks Desktop connection. Using an existing user will cause the connection to fail.
Log into Procurify as the newly created user.
Navigate to Settings → Integrations
Under Procurify API, click View. If you do not see the Procurify API option or do not see the screen below, please reach out to a Procurify Representative.
In the text field, type "QBD API Credentials" and click Create application
The page will generate a Client ID and Client Secret. Important: These credentials are only displayed once. Use the copy button to paste them to a safe location. We recommend using a Password Vault application.
The QuickBooks Web Connector can be downloaded here. We recommend always downloading the latest version.
After download, and unzipping the file, you will see a installer.exe type file, run it.
After installation, QuickBooks Desktop Web Connected is usually located in C:\Program Files. We recommend making a shortcut on your Desktop. To locate the Web Connecter, do a Cortana search of key phrase "Web Connector". Note: The .exe file will not install or open if you do not have software install permissions on your Windows machine. If so, please reach out to your IT admin.

Now that you have installed the QuickBooks Web Connector, it’s time configure the integration between Procurify and QuickBooks Desktop.

Downloading Configuration Files from Procurify

Navigate to Settings → Integrations
Under QuickBooks Desktop, click Set Up
In the pop-up window, enter your database file path. Please read the article Finding your QuickBooks Desktop path on locating your file path. Important: ensure your file path is written in lower case, or you may encounter issues.
On the next page, you will find Web Connecter files for download using the drop down on the right. Ensure to download all the .qwc files you need onto your computer.

Do not open these files when they are downloaded. You will need to edit these files following the steps below.

Configuring QuickBooks Web Connector Files

The following steps guide you on editing the Configuration files. The example screenshots will show the Vendor file as an example. The steps will need to be repeated for each of the five configuration files.

Open Windows Notepad or any simple text editor application/software.
Drag and drop the Vendor configuration file previously downloaded into the empty notepad.
Replace the username (by default, an email address) with the Client ID from your Procurify API credentials. Ensure there are no spaces at the beginning and end, and that no brackets were removed in the process.
Save and close this file.

Repeat the above steps (replacing the default email UserName with the API ClientID) for the remaining Configuration files.

Setting up the Configuration

To install the configuration files you’ve downloaded, there are a few prerequisites:

You must have permission to freely install/uninstall files on your Windows machine.
You must have Admin access to your QuickBooks company file
- There is ONLY ONE Admin account per QuickBooks company file, usually the person who created the file. If you are not sure, contact your IT admin.
You must turn your QuickBooks company file to Single User Mode

Once you are ready, simply double-click on any downloaded configuration files, and you will see two QuickBooks Web Connector pop-ups.

You may be prompted to enter a password. Enter the Client Secret generated in step 1.
On the first pop-up, click OK to proceed.
On the second pop-up, select the option “Yes, always; allow access even if QuickBooks is not running”, this will allow the integrations to run silently in the background without affecting other users.

Important: If any of the above steps fail, there should be an error pop-up window (view image below). Simply follow the instructions and triage the errors.