The repository demonstrates how to use radio buttons on Netlify forms built in Gatsby.

If you don't wrap the input in a label, the results will save incorrectly as seen below. "Small" should really be "size", since "size" is the name of the input

<input type="radio" name="size" id="small" value="small" required />
<label htmlFor="small">Small</label>

Wrap the input in a label to ensure the name of the input is used in the results.

<label>
    <input type="radio" name="size" id="small" value="small" required /> Small
</label>