Direct answer
Use the authorised sportsbook list for your location and check the NFL schedule on the listed operator’s exact domain. In the United States, check your state. In Canada, check your province. NFL.com can show odds from sportsbook partners but is not the bookmaker taking the wager.
What to check
Check the game’s date, market and whether the receipt identifies a full-game or a period bet. An NFL odds display alone does not confirm that you can place that bet locally.