Think about which elements to use: their list is on the left side of the constructor. Drag blocks, buttons and fields, enter names and hints
At any time, you can check how the form will look on the site. To do this, click on the rocket button in the upper-right corner of the constructor field. You can change something at any stage: add buttons or fields, customize the style
While you are building the form, the program writes the code to insert. The lines need to be copied and pasted to the desired page