This past weekend Sporting Kansas City played on Fox Sports 1 so that was the only way to watch the game. In prior weeks, for non-nationally televised games, MLS Live has been free for everyone and Kansas City residents have Fox Sports KC or Fox Sports KC+. The USL have always streamed their games on YouTube, at least for as long as the Swope Park Rangers have been in the league.
Going forward, the only way to watch if you live out of market is to subscribe to ESPN+, the new ESPN streaming service.