This is a paid asset, but now you can download Fast Gaussian Blur ( Mobile , URP , VR , AR , LWRP ) Free.
Detail this asset from Unity Store: Original Link
Fast Gaussian Blur Mobile URP VR AR LWRP v1.4 (Latest version)
“If possible, please buy the package to support the developer”
Works with Unity versions higher than 2017.1.0f
LWRP works only with Unity versions higher than 2019.1.0f1
URP works only with Unity versions higher than 2019.3.0f3
Supports Single-pass and Multi-pass VR
Fastest Solution on the market
This package consists of two shaders for applying the blur on the screen. This solution is currently the fastest blur I the market. Both of the shaders were tested on a low-end mobile device in the loaded scene in order to optimize the performance and fps.
SHADERS
* BLUR – The fastest blur in the Asset Store. Completely optimized blur, implemented using gaussian blur. Implemented in single-pass. Runs at 45-58 FPS on a low-end mobile device(with proper settings).
All the testing was made on low-end mobile device Meizu M2 Note in the scene containing:
-101 different gameObjects,
-101 Materials,
-1 Directional Light(realtime),
-45k polygons
 – Free Download){kind=link}