I recently upgraded an Ender 3v2 with linear rails on all axes. However, the X-Axis I purchased from Amazon ( https://www.amazon.co.uk/gp/product/B09M73XRBH ) secures the rail to the top of the X 2020 bar and not the front as a lot of people do.

The downside to mounting it on either axis is you lose a slight amount of printing area on said axis. As I very rarely use the full height, I thought it was a better option to use it as it was designed.

I couldn't find a bracket, so I remixed this excellent one from YungSnubs to screw directly onto the bracket that came with the linear rail ( https://www.thingiverse.com/thing:5543578 ).

A couple of things to note:
I printed in 100% PETG because at the end of the day it's replacing a solid metal bracket, so I wanted it as solid as possible. I'm sure much less infill would be fine but it's up to you.

Also use 2 M5x8mm screws. No bigger as they will push against the linear rail slider. And use rounded head ones so they fit in the recess of the hole, or the extruder won't sit against the plate.

You can use support blockers for the screw holes as no supports are needed for them.

Lastly, after a bit of trial and error positioning the rails in the optimum place I had to change the following settings:
X Bed Size: 222
Y Bed Size: 222
X min position: -5
Y min position: -24
X max position: 222
Y max position: 222
Z max position: 235

These might be different on your printer, I don't know, but I use very small clamp/clips, and this is the maximum I can go within 1mm inside all 4 edge clips. I can go a little higher, but I decided to keep it at 235 because I VERY rarely go anywhere near that high or i'd use my other printers and it gives a little room for my bed changing height slightly over time.

-=Print Settings=-

Printer brand:
Creality

Printer:
Ender 3

Rafts:
Doesn't Matter

Supports:
Yes

Resolution:
.2

Infill:
100

Filament brand:
Eryone

Filament color:
Black

Filament material:
PETG