The most reliable way to get high-quality English subtitles is through official streaming platforms. Depending on your region, After Ever Happy is available on several services that offer built-in, professionally translated CC (Closed Captioning):
After Ever Happy marks a massive turning point for our favorite couple. Don't let a missed line of dialogue ruin the emotional impact. Grab your popcorn, turn on those English subtitles, and get ready for the rollercoaster.
You can rent or buy the film on Amazon Prime Video. Their player allows for easy subtitle customization, including font size and color.