How To Deobfuscate ConfuserEx .NET Assembly?

No matter what I try I cannot deobfuscate this crackme https://crackmes.one/crackme/5d6c847433c5d46f00e2c390.

I have tried each & every tutorial on youTube of which this one is the best https://youtu.be/X0F_-sE-6GU. Following all the steps in the video I receive an unhandled exception at 1:47. I am unable to deobfuscate the crackme. I’ve tried so many variations of this I couldn’t possibly list them. Imagine 3-days; 9 hours a day running every variation, that’s what I’ve done.

An expert will have it deobfuscated in a few mins. Is anyone able to advise the steps with dnSpy to truly deobfuscate this crackme?

I’m not after the solution to the crackme; just how to debfuscate.