Photo Editing API with Gallery

So my site is setup for fashion design and in the members personal galleries they can buy and sell their fashions for points. I have a photo editor on the site where they can make their fashions, called Photopea. They offer API which Im making use of on my version. What I want to do is see about members being able to save their fashions straight from the photo editor to their gallery. Photopea's API says about being able to save the images to your own server but I'm not sure if there's a way for me to figure out what it'd be for my site.
Here are some links that may be needed, also keep in mind I know a large amount of HTML, CSS, and Javascript so for the most part I should be able to understand coding answers easily. I've highly customized my site so keep that in mind as well.
The Gallery: http://www.designerssociety.net/gallery/personal.htm
Page with my Photo editor (You have to click Design): http://www.designerssociety.net/h60-studio-central
Photopea API info: https://www.photopea.com/api/

Test Member Account on my site:
Username: tester
Password: forumotion

Thank you so much in advance this would be a huge improvement for my members!

Hello!
So looking at this information and the Photopea website, since it has information that needs to be uploaded to the server itself may cause the problem with the compatibility with Forumotion as the servers aren't publicly accessible to the Forumotion Users. Only certain staff have that permission. We may want to wait for a staff to confirm but I am not sure if that API will work fully with Forumotion.

Regards,
James

Yes, we do not have access to the database/server.

Yes sadly we don't give the use of our servers and database to any one not even us staff have that.

so sadly we can't help you

What about incorporating something with the use of the form on the image upload page? I know that you're able to play around with coding back and forth between the iframe and your site.
https://www.photopea.com/api/live

This is possible but as mentioned, if it remotely requires any sort of code to be added to the server or anything like that, it won't work as nobody here is able to do that for you. If you can edit it using HTML, CSS, Javascript, and JQuery using just what you can on the forumotion website then that is fine!

Cheers,
James

Yeah, I'm looking for something more in-depth possibly someone who's seen something similar coding wise. I know awhile back there were some codes so that you could edit certain profile fields from a completely different page. Maybe something with that concept where it could grab the form from the upload image page of the gallery and then just be able to get the actual image from the photo editor. I know you can grab info from the editor using javascript/jquery. I've done it to the extent of having it send a message to put certain images inside the photo editor. I feel like it has to be possible to get the image instead, since the actual editor itself has a button to even upload the picture to an image host (IMGUR) right from there.
Any kind of coding someone has seen even remotely close to what I'm describing even a link would help and I could look through it. I'm desperate to do this as much as possible.

I am about 90% sure that this can not be done on our systems with or without codes as you need to use our database systems.

Sadly I think this post is going to go nowhere fast.