1. Create an account @ sendinblue.com
2. Retrieve your API Key from the SMTP & API section of the Sendinblue website

3. Paste this API Key into the plugin's API Key settings in Bubble

To use the 'Create and update contact WITH CUSTOM ATTRIBUTES' call you will need to change the ATTRIBUTE values to match the ones in your Sendinblue account, eg. if you want to amend the attributes called 'NAME' (text) and 'AGE' (number) you would set this as below:

{
   "email": "[email protected]",
"attributes" : {
"NAME": "John Doe",
"AGE": 27
},
"updateEnabled": true
}