The registration widget will allow you to create a registration form that will allow users to register to your site, and will automatically create a new user in your database user panel and in your "_user" table. 
To enable users to register, you need to first make sure your permissions are set for 'public' to create new data in your "_user" table.

Step 1

To set your permissions follow the next instructions:

1. Go to your online database and then to "users".

2. Go to "public" and click edit.

3. Under your "_user" table, tick "create" like below:

Step 2:

Now that you have set your permissions, it's time to  set up the registration to your site.

1. Go to pro mode and then to "web widgets".

2. Drag and drop the "Registration" widget to your page.

3. You can edit the form by clicking on a field and clicking on edit, and you can delete the field by clicking delete.

4. Make sure to keep the user and password fields as they are mandatory.

Our final result after publishing:

All done! now you have a functional registration to your website, you can enter your user tab in your database and see all of your new users, control them and grant them roles.

As an example, we registered a new user named "Tester", and here is how it looks in our database:

On the next page you will be able to test the registration out live.