onerror set src code example
Example 1: img onerror
<img src="invalid_link"
onerror="this.onerror=null;this.src='https://placeimg.com/200/300/animals';"
>
Example 2: oneerror javascript image
<img src="imagenotfound.gif" alt="Image not found" onerror="this.onerror=null;this.src='imagefound.gif';" />