Customized Form - Sharepoint Online library

In SharePoint online, I have created a document library, that uses lists for the required field columns that I have selected. I have then created a customized form for the library. When I am in the site contents, and select the library, I can add an item and choose ‘edit all’ to pull up my customized form and it works as expected. As soon as I add the library to a new webpart, I am no longer able to access my customized form.

Is a customized form only available at the library level? I created one, and added the library to my webpart, and when i try to add a library item that way i’m not given the option to use my customized form for required fields.