Top mods / Sophisticated Backpacks (Unoffical Fabric port)
Not listed
Sophisticated Backpacks (Unoffical Fabric port) doesn't list Minecraft 26.3 on Modrinth. The newest release it lists is 1.21.1, on Fabric.
Open Sophisticated Backpacks (Unoffical Fabric port) on Modrinth
This is what the mod's author listed on Modrinth, not a test. A listing doesn't prove a mod runs on your setup, and a missing listing doesn't prove it fails. Versions must match exactly, and files published elsewhere, such as CurseForge, aren't counted.