Add the Fields on a Form in Microsoft Dynamics 365
After you’ve identified additional information that you would like to track in the application, you can create the custom fields on the appropriate entity and expose that new fields on a page in Microsoft Dynamics 365.
The following steps describe the process for creating a custom field and placing that field on a form.
Navigate to the form where the new field is needed.
Because the end goal is to expose the custom field on a form, the entry point for creating custom fields exists inside the personalization experience. Open the personalization toolbar by selecting Options, and then Personalize the form.