Welcome, @FreshBathRemodel. Thanks for joining the Community here! 
I had a look at the available actions for the JobTread app but I couldn’t see any sort of ‘Create Transaction’ type of action there. So I’d suggest contacting our Support team to submit a new feature request for that to be added. You can do that here: https://zapier.com/app/get-help. The feature request will be shared with the JobTread app’s developers through our internal tracking tool to flag that this functionality is needed.
In the meantime, it looks like JobTread has a Query API action. It’s an advanced action, but seems like it would allow you to make a call to their API. Perhaps you could use that action to add new transactions?
Hope that helps to get you pointed in the right direction. If you give it a try and have any success, let us know!