Hi Tom_Fitz,
Thanks for reaching out, We hold the AccountRight Postman collection which you can download. We support the API for AccountRight and Essentials however not the Postman app itself. This would be looked after by the Postman Team if there are any issues with the app itself.
Using the same key is not a problem however each user would need to complete authorization with the email address being used.
What is the user doing when they are running into trouble e.g authentication? What is the error that the user is getting when they are using the environment?
MYOB Postman collection - https://apisupport.myob.com/hc/en-us/articles/360000475775-Postman-Collections-for-MYOB-APIs
