GetDelegatedResource return empty result

Question

I want to implement GetDelegatedResource tron API function. But I get empty result.

I post this data

{
"fromAddress": "TRYQ8gSqk8BY6kqJ868UCnDqPC7LtAgaaA",
"toAddress": "TLEjNeLN1wMKiF7buc45wZzMsbk6dMUMDY",
"visible": true
}

to url https://nile.trongrid.io/wallet/getdelegatedresource

What do I do wrong?