cannot download files in pixilart.com webapp

[ComLarsic]

Hello everyone, i recently found out that www.pixilart.com has a mobile mode so i am trying to create a webapp for it.
however i cant seem to download files when testing it out using: clickable desktop.

i get this error:

qml: [JS] (https://www.pixilart.com/js/FileSaver.js:14) Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check https://xhr.spec.whatwg.org/.
qml: [JS] (https://www.pixilart.com/draw:0) Failed to load data:image/png;base64,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: Invalid response. Origin 'https://www.pixilart.com' is therefore not allowed access.
qml: [JS] (https://www.pixilart.com/js/FileSaver.js:11) could not download file

the source code is over here: https://github.com/ComLarsic/Pixelart-UT.

Does anyone know a fix?

P.S the app itself works fine, it just cant download any images