Enabling several developers to profile the same applications/on the same servers requires a Premium or an Enterprise Edition subscription. You can try the Premium Edition for free for 15 days.
Step 1: Create an environment
Collaboration happens through Blackfire environments. First, create an environment. You will need to navigate to the Organization which has the Premium or Enterprise subscription.
Please note that you will need to use the environment's server credentials on any machine where you want your team to start profiling. Those can be found under the "Settings" tab of the environment:
Step 2: Add members to the environment
Go to the "Settings" tab of each environment you created to add members.
Please make sure to use their existing account's email address to add them to the environment. If the email address you entered doesn't correspond to an existing account, your collaborator will need to create a new account. The easiest is then to create and account on SymfonyConnect with the selected email address, then signup to Blackfire.
Going further: Environment admins
Environment admins enable the account owner to delegate some rights to a team member.
Once the member has been added, you can promote him to "Environment admin":