How can I increase the font size on this page?

Site URL: https://donwilliamsonartworks.com/shop/p/countrybarn

I want to put some text in the bottom text box in the Item tab. No text size works however.
Monospace and Medium Paragraph is too small and anything else doesn't even show up.
I have no idea what that box is called or how to add any other selectable sized to try.

I want to make it larger than this is. 'THIS IS A TEST" is the Medium Paragraph size.
Can anyone help me?

Hi. You can use Monospace then share link to a product where you added text. We will try checking some solution

https://donwilliamsonartworks.com/shop/p/countrybarn

The text "This is a test' is monospace. I want to make that text larger.

Thanks

On 8/21/2021 at 9:03 AM, DonWW said:

https://donwilliamsonartworks.com/shop/p/countrybarn

The text "This is a test' is monospace. I want to make that text larger.

Thanks

The url doesn't exist

Sorry.... I made some page mods since... URL is:

https://donwilliamsonartworks.com/originals/p/countrybarn

22 hours ago, DonWW said:

Sorry.... I made some page mods since... URL is:

 

https://donwilliamsonartworks.com/originals/p/countrybarn

Add to Design > Custom CSS

/* Monospace font size */
.ProductItem-details-excerpt pre code {
    font-size: 30px;
}