getAllowance(contract, owner, approved)

Feature	Get amount of approved point of spender by owner.
Parameters	string contract address, string owner, string approved
data of SuccessResponse	object approved point balance

example

const contractAddress = "0x41EFb6902ADcb1214a7123b01af66b1D13b89864fca";
const owner = "0x4874C17C354c498cf44D2946612DBe47fBcE7E87fca";
const approved = "0x07469989b2562afF5E5C3B116CD3AA5Ef814e5a1fca";

// Note: an asynchrous request
const balanceInfo = async () => {
    const info = await mitum.point.getAllowance(contractAddress, owner, approved)
    console.log(info.data);
};
balanceInfo();

// output
{ amount: '100000' }