To get started with Redmine on Zapier, first you will need to click to connect your Redmine account to use with your Zap.
Next, a popup would appear and you'll be asked to enter your Redmine Full domain and API Key.
How to Find Your Redmine API Key
To find your Redmine API key, login to your Redmin admin account then open your Administration settings and select Authentication. Check the Enable REST API key option there.
Then, copy your Redmine API key from the My Account sidebar, and add it to Zapier’s Redmine login dialog.
Click “Continue” and if your details were correct your Redmine account will now be successfully connected.