How can I upload an image to include as a button?

Do you mean the image will be part of the form as an option from a selection?

You can use the Image Picker widget for that. 

You can also try to check these other widgets:

Image Checkboxes widgets

Image Radio Buttons widget

Image Choices widget

Or what you're asking how can you put an image to the submit button as its background?

Can you help us by giving us more details, please?

We will wait for your response. Thank you.

I want to put an image as part of the submit button of the form. I noted that in configuration there’s a field “Button Image” but I don’t know where to upload the image that I want to include.
This is the same for the Image slider widget…. where should the images be stored?
Thanks!
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The images should be uploaded to some location on internet to which you could link from your form.

You could also upload the image to your form by uploading them to the Image field and then copy pasting the link, but I always suggest using a different website instead.

Once you have the image on some location, all that you need is to use the link to it to have it shown in your form.

If you do not have your own website, then a free image hosting such as: http://imgur.com/ can be used, although in that case, it would be best to upload the same to your form.

Or by uploading it here: http://www.jotform.com/help/image_upload.php?naked=true and using the link to show it on your form.

Thanks a lot!!! It was really helpful
Regards,
Mariana de la Cruz
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On behalf of my colleagues, you are welcome! If you need anything else, please open a new thread, we will be glad to assist you.