I've used this tutorial to add an electronic signature feature to a page: https://support.totallycodable.com/en/article/create-an-electronic-signature-with-wix-code-corvid-custom-form
That's all working fine and the data is collected correctly.
I just need some sort of confirmation/thank you pop up for once it's been used so people know it worked. I've made a Lightbox but don't know how to get it to show after the signature has been submitted - the red text on Step 5 of the above link indicates something should go there but I don't know enough about coding to get it to work. Any help?