Facebookpixel ViewContent in AMP Pages - facebook

Question

I want to add the Facebook Pixels PagesView and ViewContent in my Amp Page.
Here is my Code:
<amp-analytics type="facebookpixel" id="facebook-pixel">
<script type="application/json">
{
"vars": {
"pixelId": "xy"
},
"triggers": {
"trackPageview": {
"on": "visible",
"request": "pageview"
},
"trackViewContent": {
"on": "visible",
"request": "eventViewContent",
"extraUrlParams": {
"content_category": "open article"
}
}
}
}
</script>
</amp-analytics>
The Pageview works but for the ViewContent I always get warnings in the Facebook Pixel Helper.
The resulting POST request to Facebook from AMP is this: https://www.facebook.com/tr?noscript=1&ev=ViewContent&id=xy&cd%5Bvalue%5D=&cd%5Bcurrency%5D=&cd%5Bcontent_name%5D=open%20article&cd%5Bcontent_type%5D=&cd%5Bcontent_ids%5D=&dt=o4haxxaf7ij6ugv6b3p7cy2qybh9e8rd
So it is sending all sorts of empty parameters to FB. Most of the standard event parameters for Facebook pixel are optional. I don't want that they send all the parameters. I just want to send the content_category..

Answer 1

Use img pixel. Example:
<amp-pixel src="https://www.facebook.com/tr?id=&ev=ViewContent&noscript=1"
layout="nodisplay"></amp-pixel>

Answer 2

Use following config:
<amp-analytics type="facebookpixel" id="facebook-pixel">
<script type="application/json">
{
"vars": {
"pixelId": "PIXEL_ID"
},
"triggers": {
"trackPageview": {
"on": "visible",
"request": "pageview"
},
"trackViewContent": {
"on": "visible",
"request": "eventViewContent",
"vars": {
"product_catalog_id": "category_id",
"currency": "EUR",
"content_name": "content_name",
"content_category": "content_category",
"content_type": "product",
"content_ids": "[1,2,3]",
"value": "10"
}
}
}
}
</script>
</amp-analytics>