I’ve finally figured out how to achieve this and I’m going to be posting a comprehensive tutorial for anyone that is interested in achieving a similar thing.
[UPDATE - TUTORIAL]
So I basically wanted to create a “thing” in one Bubble app (App2) from another Bubble app (App1).
Step 1 Go to App2 (the app you want to create a new “thing”) then Settings > API. Then tick the checkbox “This app exposes a Workflow API” (see green arrow) - you might want to also tick the second checkbox below in case you would like to expose App2’s data to any other application - not just a Bubble app. This will then show the “API Workflows” page which is at the bottom of the page menu. Then as you can see by the other highlighted checkboxes, decide what data you would like to expose to App1 by ticking them.
Step 2 Create a new API Endpoint. The “Key” should be the field that is in the “thing” you are creating and the “Type” should be the type of data (i.e. text, number, date etc).
Step 3 Now go to App1 and use the Bubble App Connector plugin to make an API action call. Get your Private Key from Step 1’s API Token (haven’t shown it in the screenshot but it’s literally just below the checkboxes). Your app domain is your bubble app or if you’ve got a custom domain linked to your app you should use that. “Add an API Call” and find the name of your API Endpoint (the one you created in step 2). Set the “Use as” to “Action” and “Authentication” to “API key”
Step 4 This is the part I was confused with. Go to the page where you want to trigger the action and create a workflow that runs it. Start a workflow> Add an action by clicking “Plugin” > Run “(name of your app2)”, then fill in the inputs for the Keys you created in Step 2. That’s it your done!