Step1: Get into the Builder and go to the 3rd last tool to the toolbar at the left corner of your screen.
Step2: Select the 'CUSTOM HTML' tool from the toolbar.
Step3: With this, the typebox will appear on your screen to write the desired code.
Step4: Click on the typeBox and a toolbar will appear at the right side to manage its setting and for pasting the code.
Step5: Select 'CODE' from the dropdown and paste the code in the area indicated in the image below: