Here is another tutorial for you.
The requirement is to add a ribbon button so a Customer Service Agent can easily create a Phone Call with minimal clicks in the Unified Client Interface of Dynamics 365. We will also auto-populate the values in the Phone Call form.
Step 1: Create a web resource js file where you will write the custom script to open the quick create phone call form.
Step 2: Add a custom ribbon button in the Contact form using the Ribbon Workbench.
Tip: Make sure that the solution you will open in the Ribbon Workbench only includes the entity you need to modify without all the assets. This will make publishing quicker.
Step 3: Add a Phone Call command in the Ribbon Workbench with CRM Parameter of PrimaryControl. This is the executionContext where you can easily get the attributes of the form.
Step 4: Write these codes:
Your result:
Learn to Inspire 
Thanks for catching that. I didn’t realize I snag the original code I had. I had to move the retrieval of contact details in the same function because of retrieval delays.
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Nice. Good point with: entityFormOptions[“useQuickCreateForm”] = true;
Instead of deprecated Xrm.Utility.openQuickCreate methods.
Just the second screen seems to be broken.
getContact method is already implemented with WebApi on the first one.
Also I think in getContactObject method should be lookupData instead of lookupItem.
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