Argon2 is used in tutor registration to store password hashes instead of cleartext passwords, supporting later authentication. section 8.3
Tutor registration
When a tutor submits registration credentials, the application uses Argon2 hashes for storage in Postgres alongside the tutor ID and username. section 8.3
sqlx = {version = "0.3.5", default_features = false, features =
["postgres","runtime-tokio", "macros"]}
rust-argon2 = "0.8.3"
awc = "2.0.3"
The dependency listing identifies the Rust crate and version used for password hashing. section 8.3

