will this guide apply to my phone?

Hi peanut boi,

If you are just replacing the glass, then yes that guide will be sufficient; of course you've already noted that the camera/lens arrangements are different on the two phones, but the basic procedure is the same.

Apparently you can just replace that whole housing piece that holds the glass if you prefer; the Spanish site Nadie Me Llama Gallina has a guide showing how to do that particular repair. The site is in Spanish, but if you use it with the Chrome browser's translation, it is quite usable and well written.

Manuales / Samsung Galaxy S20 Ultra / Camera lens - Nadie Me Llama Gallina

As far as personal preference, you're going to have to deal with a lot less broken glass using the whole housing method, but I'm sure the glass only repair will be inexpensive and not that difficult; you just have to do a good job cleaning. Or you could do something halfway in between the two; follow the housing guide far enough to take off the back of the phone; that way you won't have to worry about getting glass chips in the cameras as you remove the lens from the rear cover, but you will have to deal with gluing the rear panel back on the phone when you're done, so it's all a tradeoff, safety vs. cost vs. effort.

Good luck, and let us know how it all turns out!