Why do I get this error "CURL error 56: Received HTTP code 400 from proxy after CONNECT (see http://curl.haxx.se/libcurl/c/libcurl-errors.html)." on NextPost Postcode Instagram Script?

Envato Customers Web and Code
1

Hi,

I am using NextPost Postcode script to run Instagram management via my website which is hosted by Namecheap’s Shared hosting.

When I tried to add a Instagram account with a proxy setting this error appears.
“CURL error 56: Received HTTP code 400 from proxy after CONNECT (see http://curl.haxx.se/libcurl/c/libcurl-errors.html).”

Please check this screenshot: https://i.imgur.com/CStBbPN.png

Is it because I am using Shared Hosting?
Should I use VPS hosting with cPanel?

Any idea guys?