Website crashed when replacing 1 word, only white screen visible on the website

To replace some words in my overall website I downloaded Real-Time Find and Replace.
It says when I open the plugin that:
“This plugin will replace HTML code AFTER it is written by the WordPress engine,
but before it is sent to a user’s browser.”
So it seemed safe to make changes to my website without backing it up since the original (from the WordPress engine) code is not replaced.
I just entered 1 word and replaced it with 1 other word and afterwards, when I open the website, it crashed. But it says the HTML code was replaced AFTER it was written by the WordPress engine.
So I would like to restore my website and from what I can understand remove the blockage between my website and the user’s browser and that would work because the full original code is still in the WordPress engine.

How could I do this?

Btw: I already did the process the other way around by putting the 1 word left instead of right and the other right instead of left so it would be restored but that did not work either.
When I open my website currently it is only on a white screen.