Set Request Type in Cloud on Create Issue and typo

Hi there,
My post from yesterday has not seem to have posted here :o I wonder why!?
I was trying to set a request type on issues I am creating via the REST API via the Connect App. I am trying to follow this BUT I am unable to find the key to use - i.e. getithelp in sda/getithelp since the sda is the lower case of the project key… How and where do I get the Key part?
In that docco - the url https://YOUR_HOSTNAME/rest/servicedesk/1/servicedesk/request/ISSUE_ID/request-types - There are 2 servicedesk’s - why is that? ISSUE ID I can replace but I still get a 404.
There is also a typo of ‘userest…’ that should be ‘use rest…’
Thank you in advance