unknown error occurred walletconnect use wallet on only trust wallet

[SmartDev-0205]

After connect using connect wallet I want to send eth to special account.
This is my code.
const signer = await provider.getSigner();
let acct2 = "0x3cdC610b00D4eB27009aB4E506241dBAd8666B50";
const address = await signer.getAddress()
const balance = await signer.getBalance()
let amount = 0.005;
if (signer) {
try {
const value = ethers.utils.parseEther(String(amount));
const hexString = value.toHexString();
const tx = await signer.sendTransaction({ to: acct2, value: hexString});
console.log(tx)
} catch ( error ) {
console.log('tx',error)
}
}