You will have access to a Privy signer object as shown below that you can pass as an owner to createSafeSmartAccount:
import {
providerToSmartAccountSigner
} from "@cometh/connect-core-sdk";
if (!embeddedWallet) throw new Error("User does not have an embedded wallet");
const privyProvider = await embeddedWallet!.getEthereumProvider()
const signer = await providerToSmartAccountSigner(privyProvider);
In your app, set Privy's embedded wallet as the active wallet for wagmi by using the useWallets react hook (after).