You need a signing profile to deploy to devices. I don't think it would be legit any other way about it. I would think that what you asking falls outside some ToS somewhere. If you want to deploy to a device, you must register with Apple and pay the developer cost to get a provisioning profile for actual devices.
If there is another way (legit), I would sure like to know too...
No valid iPhone code signing keys found in keychain
That's because you don't have any keys... Just as it says which you already know. You must pay/register with Apple to get this.
With Regards,
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