Can't expand php snippet inside html attribute?

Question

I have a snippet to expand php with echo.

    "php variable": {
        "scope": "html",
        "prefix": "pv",
        "body": [
            "<?php echo $1 ?>"
        ],
        "description": "PHP expand"
    },

and image html tag

<img src="pv" alt="">

And pv don't work. Now to use this snippet, i need to type pv outside image tag and move inside. How to fix that?

I tried to use snippet for js