error: Mixed Content: The page at ____' was loaded over HTTPS, but requested an insecure XMLHttpRequest endpoint This request has been blocked

I deployed my website and it contains an API that will not work and in console, it shows some error but the site will work properly in my localhost.

error: Mixed Content: The page at 'index.html' was loaded over HTTPS, but requested an insecure XMLHttpRequest endpoint ---"URL". This request has been blocked; the content must be served over HTTPS.