Welcome to the community, @Kate_Kiriakou!
As @Moe mentioned, adding an image into the body of a form is only possible with 3rd-party solutions, because Airtable’s built-in form is extremely basic with very little functionality. Airtable lets you add 1 image + 1 banner to the top of the form, and that’s it.
Moe’s form solution at MiniExtensions.com is, by far, the best form on the market for integrating your Airtable data with a form. This is the form that most people should look to first if they are trying to integrate their Airtable data with a form.
Another option for integrating your Airtable data with forms is JotForm + On2Air Forms.
However, you said that you just need a static image added to your form, so it sounds like you don’t need to dynamically work with images from your database.
In that case, you can use ANY 3rd-party form builder on the entire market. Some of them, such as JotForm, include built-in Airtable support, so when your form gets submitted, the record is automatically added into Airtable.
For all other form software (or for more advanced handling of your JotForm form), you would need to turn to Integromat or Zapier to integrate the form with Airtable. (Note that Integromat is superior to Zapier.)