First: Connect to Stripe 

NOTE: this may have already been done in test mode - if so the button will say "Connected" -  in this case skip to step 2: "Copying your Stripe webhook from your website"

1. Go to "Donations"
2. Go do "Settings" under "Donations"
3. Go to "Payment Gateways"
4. Select "Stripe" 
5. You should see the "Connect with Stripe" button

Second: Copy your stripe webhook from your website

1. Locate the webhook URL and copy

Third: paste your Stripe webhook in Stripe 

After logging into your Stripe account:

1. Go to "Developers"

2: Select "Webhooks"

3: Select "+ Add endpoint"

4. Paste webhook URL in the "Endpoint URL" field

5. Select "receive all events"

6. Select "Add endpoint"

With the webhook properly pasted, your screen should look like this: