Create item with link to document content type using rest api

Hi All,

I have a lib with two content types : document type & link to document 

document type content type is set as default, so when user upload it get associated with document content type

on save button I am calling presave and I want to create a item with link to document type content type in another folder of the same library but I am unable to do so

Please can anyone help me how to create item with link to document type content type using rest api ? 

Thanks in Advance, Jiniv Thakkar