JS HTML
(quick guide & example)
JUST AN EMPTY CANVAS <canvas id="demo" width="200" height="200"></canvas>
DRAW BLACK SQUARE let ctx = document.getElementById ("demo").getContext("2d"); ctx.fillRect(50, 50, 100, 100);
GET CANVAS let c = document.getElementById("demo");
CREATE LINK let a = document.createElement("a"); a.download = "IMG.PNG"; a.href = c.toDataURL("image/png");
"FORCE DOWNLOAD" a.click(); a.remove();