I’m trying to transfer ICP but am getting the following error:
Reject text: IC0503: Canister b4q7m-7iaaa-aaaaa-aaerq-cai trapped explicitly: IDL error: unexpected IDL type when parsing Nat
below is the relevant code snippet. Does anyone see any apparent reason for the error?
public shared(msg) func transferICP(amount: Nat, canisterAccountId: Account.AccountIdentifier) : async Result.Result<(), Error> {
let callerId = msg.caller;
let userProfile = Trie.find(
profiles,
key(callerId), //Key
Principal.equal
);
switch(userProfile) {
case null{
#err(#NotFound)
};
case (? profile){
let userJournal = profile.journal;
let status = await userJournal.transferICP(Nat64.fromNat(amount), canisterAccountId);
if(status == true){
#ok(());
} else {
#err(#TxFailed)
}
};
};
};
the userJournal.transferICP() function that is used in the above code snippet is defined below 
public func transferICP(amount: Nat64, recipientAccountId: Account.AccountIdentifier) : async Bool {
let res = await Ledger.transfer({
memo = Nat64.fromNat(10);
from_subaccount = null;
to = recipientAccountId;
amount = { e8s = amount };
fee = { e8s = 10_000 };
created_at_time = ?{ timestamp_nanos = Nat64.fromNat(Int.abs(Time.now())) };
});
switch (res) {
case (#Ok(blockIndex)) {
Debug.print("Paid reward to " # debug_show principal # " in block " # debug_show blockIndex);
return true;
};
case (#Err(#InsufficientFunds { balance })) {
throw Error.reject("Top me up! The balance is only " # debug_show balance # " e8s");
return false;
};
case (#Err(other)) {
throw Error.reject("Unexpected error: " # debug_show other);
return false;
};
};
};
edit: I think it may be something wrong with the way I’m sending the recipientAccountId to the backend, but I’m not quite sure what exactly the issue is. below is the front end code when I convert the address from a text to a byte array then send the request to the backend:
const onSendConfirm = async () => {
console.log(fromHexString(recipientAddress));
const status = await actor.transferICP(parseInt(amountToSend), fromHexString(recipientAddress));
console.log(status);
};
here is the definition of the fromHexString() function:
export const fromHexString = (hex) => {
if (hex.substr(0,2) === "0x") hex = hex.substr(2);
for (var bytes = [], c = 0; c < hex.length; c += 2)
bytes.push(parseInt(hex.substr(c, 2), 16));
return bytes;
};