This is a paid asset, but now you can download Third Person FreeClimb Add-on Free.
Detail this asset from Unity Store: Original Link
Third Person FreeClimb Add-on v1.2 (Latest version)
Third Person FreeClimb Add-on v1.1
Third Person FreeClimb Add-on v1.0.4
Third Person FreeClimb Add-on v1.0.1
FreeClimb Add-on * THIS ADD-ON REQUIRED THE BASIC LOCOMOTION PRO TEMPLATE VERSION 2.5.0 OR HIGHER*
FreeClimb Official Add-on Plug & Play
With the FreeClimb system you can climb on any surface but it’s more used for walls or cliffs.
With this add-on you not only get the freeclimb but also the knowledge to create custom modular add-ons without changing the core of the controller.
* Required Basic Locomotion 2.5.0 or higher, if you need a different version to work with the previous versions please contact support
** MeleeCombat & Shooter already contain the Basic Locomotion
***Animations are not included but there is a link to download already setup animations, you just need to import and hit play.