Hey,

Append to all Users and API keys allows you to give access to this environment to users and API keys which already exist in the system.

When you create API keys and Users, you assign them either a set of environments - or all environments. If all environments is applied, then they will automatically receive access to new environments created, however, if only a subset of environments are selected for each user, ticking this box will add the new environment to their permissions.

An example System:
User 1: Access to All Environments
User 2: Access to Company A Environment

You create Company B as a new environment:
If you tick this box: User 2 will be automatically given Company B as an environment they have access to, User 1 will receive this environment as part of their All Environments permissions.

If you do not tick this box: Only User 1 will have access to Company B environment, you will have to manually add the environment to User 2 - or any other user you wish to grant access through the user management window.

Hope this helps!

Cheers

K