How to query a uint256 input contract function via Etherscan's API?

Question

I'm trying to query a contract function that takes uint256 as input via Etherscan's API but I keep getting error messages. The format I've realized should be as follows based on this answer:

http://etherscan.io/api?module=proxy&action=eth_call&to=[address]&data=0x[function hash]000000000000000000000000[read input]

I got the function hash from remix but I can't find what should be added after it for a uint256 input.

What's the address of the contract, and the name of the function? — Richard Horrocks, May 03 '21 at 08:11
https://etherscan.io/address/0x60f80121c31a0d46b5279700f9df786054aa5ee5#readContract ownerOf — Curtis S., May 03 '21 at 08:37

score 2 · Accepted Answer · answered May 03 '21 at 09:18

The argument must be in hex, padded to 32 bytes.

For example, for tokenId 200 (0xc8 in hex):

https://api.etherscan.io/api?module=proxy&action=eth_call&to=0x60F80121C31A0d46B5279700f9DF786054aa5eE5&data=0x6352211e00000000000000000000000000000000000000000000000000000000000000c8

Correctly returns:

{"jsonrpc":"2.0","id":1,"result":"0x000000000000000000000000b687a0a94d2daeec6814b659c4fb3db3768ff2a1"}

Which is the address of the owner of that token, again padded to 32 bytes.

How to query a uint256 input contract function via Etherscan's API?

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