How to call servicenow scripted api from salesforce

Hello,

We use to get tickets created in Servicenow from salesforce (means from salesforce, they use to launch a record producer).

Now the requirement is when ticket in salesforce is moved to particular stage, it should auto create a ticket in SNOW with no need to manually submit SNOW form from salesforce.

As form needs to be submitted, I thought I can create a scripted API in SNOW which when called from salesforce will submit request (using cart API) 

Is this correct way? Can someone please share supporting documents or let me know how can I start this from scratch?

Thanks,