change

app/controllers/sync_forge_controller.rb

@@ -46,8 +46,15 @@ class SyncForgeController < ApplicationController
       if User.exists?(login: u[:user_params][:login])
         SyncLog.sync_log("=================sync_to_user_been_exists====#{u[:user_params][:login]}")
       else
-        new_user = User.new(u[:user_params])
+        if u[:user_params][:mail].blank?
+          u_mail = "#{u[:user_params][:login]}@example.com"
+        else
+          u_mail = u[:user_params][:mail]
+        end
+        new_user = User.new(u[:user_params].merge(mail: u_mail))
+        
         username = new_user.login
+
         password = "12345678"
         ActiveRecord::Base.transaction do
           interactor = Gitea::RegisterInteractor.call({username: username, email: new_user.mail, password: password})