I can not insert the code on the site

I put the code of Airtable form, but it does not appear on the site. What to do?

Here is the code

Only I do not understand anything in the codes, so simple explain the sequence of my actions

I am no expert but it would seem to me that the best way to add this to your site is by using adding HTML iframe provided in the editor. ADD > More > Embeds and select HTML iframe… place on site and edit to add the code you mentioned. Should do the trick. Happy editing.