Hi @bhavinrudani ,
Shopify changes fast, so the Shopify of 2015 may not reflect the Shopify of 2019. For this reason, I recommend starting a new thread rather than reviving an old one. I’ve locked this post to ensure that our forums remains a curated, up-to-date, knowledge source.
It sounds like you may not be passing the proper Content-Type header value. For app proxies you want to pass application/liquid. This is all explained in detail in our documentation for app proxies.
If you still need help with this, please open a new thread.
Take care!