Want fiancé to admit cheating before marriage

After proposing to my fiancée, I checked her phone (after she’d gone through mine in the past) and found clear evidence she’s been seeing other men, even during our relationship. She denies everything, despite me strongly hinting that I know something.

For example, I found a video proving she spent the night at an Airbnb with a guy. That same night, she picked a fight with me over nothing, which I now realize is likely her way of protecting herself—causing a falling out so she could justify her actions to herself or avoid accountability later(if I was to find out) I’ve also seen messages confirming she cheated, including plans since being engaged to meet someone soon

When I suggest she might have done something like that, she first denies it, then shifts the conversation to criticizing me, (seemingly as justification which is obvious as now know the trust) but before, I’d be confused because I genuinely put her first most of the time and couldn’t see how she could say otherwise.

I want her to confess without me admitting I went through her phone. If she came clean, owned up to everything, and treated it as a mistake, I’d consider moving forward because I love her and believe we could rebuild trust.

But instead, even when I ask if there’s anything she needs to tell me, she insists she’s done nothing wrong. There’s no remorse, no acknowledgment, and no effort to ask for forgiveness.

Only found all this out within the last couple days

How do I handle this?

Edit: for the people saying “why do this to urself” etc please understand iv been in love with this woman for years and only found all this out within the last couple days

TL;DR I found evidence my fiancée has been cheating, even after our engagement, but she denies everything. I love her and might forgive her if she confessed, but she refuses to own up. How do I handle this?