How can I create rule that send email to new user a welcome message

You don't say what you're having trouble with. This is a pretty easy task - the event you want is "After saving a new user entity" and the action you want is "Send email".

There are a lot of examples here: https://git.drupalcode.org/project/tr_rulez/-/tree/2.0.x/rules_examples/...

For example, rules.reaction.set_a_role_for_new_users.yml shows you how to take an action when a new user is created, and rules.reaction.notify_user_of_deleted_comment.yml shows you how to send email when a particular event occurs.

For more information about how to use Rules and how to use these examples, see https://www.drupal.org/docs/contributed-modules/rules-essentials →

Automatically closed - issue fixed for 2 weeks with no activity.