The Hallmark Movies Now app is available for Samsung TVs made after 2016. You can tell if your TV is made after this year by looking into the model numbers here. You can find help in interpreting these model numbers to determine the year of your device here.
To download Hallmark Movies Now on your Samsung TV or Blu-Ray player, search the app store on your Samsung device Hallmark Movies Now. You can then follow these instructions here to activate HMN.