Create authentication request

Creates a new authentication request that can be executed by the auth dapp.

Important:

• The authChain field is required and will be validated.
• Signature validation is performed using @dcl/crypto Authenticator.
• The dcl_personal_sign method is rejected, as is signing a Decentraland ephemeral message under any other method. Ordinary personal_sign / eth_sign requests are accepted.
• The request will expire after the configured expiration time (default: 5 minutes).