How to change 'aggregate rating' with this structured data code

[lifebefore20]

I used Feed Army's structured data code to help Merchant Centre recognise all of my variants, which worked great. The aggregate rating is setup to pull shopify review however, and I use Feefo. 

Does anyone know how to pull Feefo data instead? 

This is the section of code that needs editing:

{%- if product.metafields.spr.reviews -%}
{%- assign fa_rating = product.metafields.spr.reviews | split: '"reviewCount": "' | last | split: '"' | first | plus: 0 -%}
{%- if fa_rating > 0 -%}
,"aggregateRating": {
"@type": "AggregateRating",
"ratingValue": {{ product.metafields.spr.reviews | split: '"ratingValue": "' | last | split: '"' | first | plus: 0 }},
"ratingCount": {{ product.metafields.spr.reviews | split: '"reviewCount": "' | last | split: '"' | first | plus: 0 }}
}
{%- endif -%}