Here's how I added a custom field to the Admin Pages:
- console "npm install" at the root of the project
- console cd to Themes/Adminlte and "npm install"
- create your db migration (I added a field to the page module) and migrate
- in the partials for the Page module add your field to edit and create blades
- in Modules->Page->Assets->js->components edit the 3 .vue files to add the new field
- console cd to root of project "php artisan asgard:module:publish Page"
- console cd to Themes/Adminlte and "npm run watch"
- console cd to root of project "npm run watch"
- house keeping "php artisan cache:clear" and "php artisan view:clear"
You should now see your field in the create and edit of the backend of your site. Remember to add the translation if the field is translatable.