As of VRChat SDK - Avatars , there's no way to edit an avatar's "Acknowledgements" from the VRChat Builder in SDK; this must be done from the VRChat Home website.

Meanwhile, users can edit the Avatar Name, Avatar Description, Primary Style, Secondary Style, Tags, and Content Warnings from the SDK.

Please add Acknowledgements editing optionally to VRChat SDK - Avatars. This is meant to reduce avatar creator friction by removing a necessity to visit VRChat Home website to setup acknowledgements in Avatar Info when uploading new avatars.