If you do not want to manually install ASI files, there are two prepackaged solutions:

You can find the latest version on the official Widescreen Fixes Pack site or via GitHub. Installation: Extract the downloaded .zip file.

Search for "GTA San Andreas Essentials Pack 2024" on ModDB. This is a 50MB installer that includes SilentPatch, Widescreen Fix, and the 1366x768 registry tweak automatically.