You can download the Welldone wallet extension here.

You can access the codes used in the video for the move.toml file below 👇

[package]
name = "devhub"
version = "0.0.1"

[dependencies]
Sui = { git = "https://github.com/MystenLabs/sui.git", subdir = "crates/sui-framework/packages/sui-framework", rev = "framework/devnet" }

[addresses]
devhub = "0x0"