Stripe isn’t sending back $_POST[‘wp-simple-pay’]

I’m using stripe for checkout, and i connect to stripe via stripe.js and process stripe responses via php. So I’m doing a basic stripe charge(im including the wordpress shortcode because I’m using the wp simple pay pro plugin):

[stripe payment_button_label="GIVE BY CARD" success_redirect_url="my-domain
successpage" failure_redirect_url="my-domain-failurepage"]
    [stripe_amount]
[/stripe]

I’m using test mode and have them set in my plugin’s admin section.

So after I do a successful stripe checkout, i don’t get a response from stripe(ie $_POST[‘wp-simple-pay’] is not set)…what am i doing wrong?

EDIT

also I’m not getting

$_POST['wp-simple-pay-pro-nonce']

from the stripe response as well…is there something wrong with the plugin’s configuration by any chance?