The movie "Forever My Girl" can be watched by purchasing or renting it on platforms such as Amazon Video, Apple TV, Fandango At Home, and Plex. It is also available for free streaming on Hoopla. Additionally, you can buy it on DVD or Blu-ray from Barnes & Noble. Some sources indicate it may be available on Prime Video and Viaplay, depending on location. There are also full movie versions available on YouTube channels, though availability may vary. In summary:

• Buy or rent on Amazon Video, Apple TV, Fandango At Home
• Stream free on Hoopla
• Purchase DVD/Blu-ray from Barnes & Noble
• Check Apple TV and Prime Video for availability
• YouTube full movie uploads exist

This provides several options to watch "Forever My Girl" depending on the preferred platform and format.