You must approve a custom object before you can use it. The process is slightly different for new custom objects and ones that you've edited.
Approve a New Custom Object
You've created a brand new custom object. Here's how to approve it.
In Admin, click Marketo Custom Objects and select an object that's in a Draft state.
Click the Custom Object Actions drop-down and select Approve Object.
Approve an Edited Custom Object
After you edit an approved custom object, you must approve the draft to return the custom object to an Approved state.
When you edit an already approved custom object, it receives an Approved with Draft state.
When you're ready to approve the draft, click the Custom Object Actions drop-down and select Approve Object.
A preview displays the items that were changed in the draft. Click Approve.