I found that and used a wordpress plugin to post content on to the page.
I also want to know if you can use the same technique to auto-fill a field in a subsequent form. I did try the same code as i’d used on the page but it didn’t work.
Essentially the first form is just gathering postcode. We then re-direct user to a new page to fill in a bigger form and i’d like the postcode field auto filled based on the input from the previous form