I went looking for an official English version of 'I Love You' a while back, and the situation is a bit specific. There isn't a single, universally recognized manga with just that title; there are several series like 'I Love You, Baby' or stories that have 'I Love You' as part of their name. For the most common one people ask about, often a romance series, I haven't found a full official print or digital release under a major English publisher like Viz or Kodansha USA. That usually means the official translation route is a no-go for a complete physical volume.
What does exist officially are often digital chapters. Some platforms, like Comikey or INKR, sometimes license shorter series or specific chapters for English release as part of their catalogs. I recall seeing a few 'I Love You' related one-shots or promotional chapters available legally on such apps. They operate on a freemium model, where the first chapter is free, and you use passes or a subscription to unlock more. It's worth checking those apps and doing a direct search; the title might be listed in its original romanized form.
My approach when I can't find a clear answer is to search for the original Japanese title. If you can find that, you can plug it into the websites of publishers like Shueisha or Shogakukan to see if they list an English digital version. Sometimes, the official translation is bundled within a digital anthology rather than standing alone. Without that original title, it becomes a real scavenger hunt through various legal digital storefronts, which is frustrating but part of the process for less mainstream romance titles. I ended up reading some similar feeling series on Manga UP! instead, which had a comparable vibe.