This one keeps popping up on forums! I had the same question a few months back. It's a classic 'contract marriage to real feelings' trope story, originally serialized on a platform like Webnovel or GoodNovel. Those sites usually have a 'coins' system where you read free for a bit, then hit a paywall.
My method was to check if it was part of a subscription service like Kindle Unlimited. Sometimes these books get compiled and published there. I snagged it that way with a free trial. Alternatively, some public library apps like Libby or Hoopla have partnerships with digital publishers. It's a long shot, but searching the title there is worth five minutes.
If you're comfortable with less-than-official routes, there are reader forums where people share downloadable files. I stumbled across a PDF for a different novel in a Discord server once. The quality was rough, with weird formatting and missing chapters, which honestly ruined the pacing. For 'CEO's Ugly Bride', the plot relies on slow-burn tension, so a choppy read might not be worth the hassle. The author probably makes a few cents per read on the official app, which is something to consider if you end up loving it and want to support more stories in that vein.
Honestly, after jumping through hoops, I just used the official app and watched ads for free chapters. It was slower, but it felt less disruptive than hunting for broken links every few days.