1)

 Add proper URL rules and select "Validation"

2)

Capture an element and select a validation type

3)

Enter a message for the selected validation type and click on "Save"

4)

Select "Form Submit"

5)

Select the submit button, which in this case is - "Sign Up" 

6)

Click "Save"

7)

Publish this tooltip and it's respective parent folders

8)

As we have selected password as a mandatory field for the validation type, it means if we skip this field the submit button will be disabled by MyGuide

9)

When we enter values in the password field, submit button will get enabled