Receipt not attached on Expense API in Zoho Books

I am trying to upload a file for expense using this API :

https://www.zoho.com/books/api/v3/expenses/#add-receipt-to-an-expense

I have converted my file to Byte64 string and uploaded the file. I have got the successful response status that file has been uploaded.

But then when I check that on portal it does not appear on portal, I tried asking support on email but they disappeared after few replies.

I even called the Get Expense Receipt API (https://www.zoho.com/books/api/v3/expenses/#get-an-expense-receipt) and it also say that :

{
    "code": 33003,
    "message": "Receipt not attached."
}

This is the successful response that I get :

{
    "code": 0,
    "message": "The expense receipt has been attached.",
    "error": null
}


I don't know what am I missing uploaded file should appear on ZOHO BOOKS PORTAL for same EXPENSE