Using the Butler, select "Add a new bidder" fill in the bidder's First and Last Name, phone number and email, then hit the complete button. 

If you do not enter a bidder number the system will assign them the next available bidder number.

The bidder will then receive a Welcome text message that can be edited in the admin under Software Settings > Auction Settings > Bulter Settings. Remember to use your shortcode [u] to include the bidding link.

You can find any new bidders added this way under your admin in the Bidders > Manage Bidders tab.