Welcome to the forum, it's nice to see that Idena continues its development now and extending its blockchain to the development of sports betting. But what confused me was that for registration on app.idena.io you need to import your own encrypted, but private key of your wallet, of course you can not use the main wallet, but still it pushed me away, so be careful with this.
Well, the authorization happened on the side of app.idena.io web-application which is 100%
open source. Also, to work via web-application you would need a special API key, which you could generate buy running your own shared node or by buying it in the shared node marketplace. API keys + Shared Node URL it's like an access to the API interface of the blockchain. In case if you have doubts you could create a wallet only for bets for example and keep your savings on independent cold wallet that you can create buy running your own node.
For now importing your encrypted private key is the only method that is accepted.
Please note that we are just developing the betting platform in partnership with Idena core team. If you want to know about the roadmap or any futher questions related to the future plans on improving Idena auth mechanism it would better to ask in the comments section of the latest
Idena Chronicles.