Embed MultipleEntryReferenceEditor component inside custom EntryEditor UI component

Hi, I would like to create my own extension, but I don’t know if there is an option to embed MultipleEntryReferenceEditor in the custom entry editor. MultipleEntryReferenceEditor requires propa sdk with type FieldExtensionSDK and I don’t know where to pass it from. Is there any option to add such fields for the custom editor? Can these only be simple fields of type text, number etc. Has anyone ever had a similar problem?