The first thing you'll need to do is select Insightly either as an action or as a trigger.
The next step is you'll need to add your Insightly account to Zapier. This can be found by logging in to your Insightly account, clicking the profile icon in Insightly and select User Settings.
On the next page, scroll to the bottom to locate your API key.
Copy and paste that into the connected account account box!
If all works well you should see the following with a successful account validation. If it fails you should check to make sure you copied the API key and removed any whitespace before or after it.