SIM900 to Firebase functions

Hello, Im trying to connect my SIM900 to my firebase function using http get/post. If i use https url, it gives me an error 603 which is DNS error. If I remove “s” and make it just http, it gives me error 302 which is Redirect error. Any suggestion would help, thanks.

Hello and welcome! What interface are you using to communicate with the server? TCP, HTTP? In any case, you need to do extra steps in order to use TLS/SSL besides just typing the address with https: or htttp:.
Even if you set the SIM900 properly to work with TLS/SSL, the server might still deny it access, since it uses a really old implementation of those protocols (which is not safe by today standards, so you might as well go with just http).