When I tried to attach a jpg image to this post:

https://sopuli.xyz/post/6943637

I got:

SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data

These are the image details:

$ identify image.jpg
image.jpg JPEG 970x308 970x308+0+0 8-bit sRGB 17005B 0.000u 0:00.000