You can install a GiveForm on a Squarespace website either directly on a page or in a popup (modal).
Step 2. At the top right of the screen, click Embed My GiveForm.
Step 3. Copy the embed code based on whether you want to embed your form directly on a webpage or in a popup.
Step 4. In Squarespace's website editor, open the page where you'd like to embed your GiveForm. Drag an Embed Code box to your page.