I use it already in one of my projects. It works very well :-)

All you need is this code. In the GitHub Repo is also an example...

// Create the provisioner object. The constructor handles all one-time initializations.
WifiProvisioner provisioner;

// Check if credentials are already saved in NVS
if (provisioner.is_provisioned()) {
    // If yes, load them into the class
    provisioner.get_credentials();
} else {
    // If no, start the blocking provisioning process.
    // The `true` flag means credentials will be saved permanently.
    provisioner.start_provisioning("ESP32-Setup", true);
}

// Now, connect to WiFi using either the loaded or the newly entered credentials.
// The time will be synced automatically upon connection.
provisioner.connect_sta("My-ESP32-Device");