I just found that this package didn't work in backpack 6.3 because of middleware Backpack\CRUD\app\Http\Middleware\AuthenticateSession in config file config/backpack/base.php,
remove the AuthenticateSession::class can make impersonation worked or alternatively to subclass AuthenticateSession::class and edit/modify following lines.
if ($request->session()->get('password_hash_'.backpack_guard_name()) !== $this->user->getAuthPassword()) {
$this->logout($request);
}
I just found that this package didn't work in backpack 6.3 because of middleware
Backpack\CRUD\app\Http\Middleware\AuthenticateSession
in config fileconfig/backpack/base.php
,remove the AuthenticateSession::class can make impersonation worked or alternatively to subclass AuthenticateSession::class and edit/modify following lines.