The real problem here might be, there are two sites in the name of betonline; Betonline.ag and Betonline.com
Betonline.com might be a fake one. I just tried http://www.betonline.com/sportsbook which is not at all loading.
(I checked this alone for options for bitcoin option as OP mentioned about this domain).
Betonline.ag seems like a professional site and they are listing bitcoin as one of available payment option.
On a quick search on bitcointalk I found this : ***WARNING*** PLEASE DO NOT BET ON BETONLINE.AG
But on the page with the link BetOnline review - https://coinpedia.org/earning-site/betonline/ reviewed exactly this site - BetOnline.ag
But the screenshots are from https://www.betonline.com/ and video too This is confusion.
And I agree with the opinion that you shouldn’t bet on BetOnline.ag, although BetOnline.ag accept BTC and LTC diposits