Is it possible to add a loading screen/box/icon during the upload of data, when someone submits a form?

Hi.

When someone fills out my form and clicks submit they get a success message saying “Your content has been submitted”, but it can take 5-15 seconds before this pops up. I have added loading effects while the data is uploading, but I would like to make it even clearer that their data is being uploaded, so there is no room for confusion at any point.

I have found guides on adding lightboxes and other events when a form has been submitted, but I can’t seem to find any guides during the upload of the data. Ideally, I would like it to be a big box in the middle of the screen with a loading icon that disappears when the upload is finished. If you have any suggestions to a workaround or different way to achieve this, I would love to hear it!

I highly appreciate any help.

Hey, how did you add loading effects while uploading data?