I've been using the (/v1/user) endpoint and others with a valid API key for a long time and I recently noticed it stopped working after June 2nd. It now returns:

"""
{
"Error": [
{
"error_description": "Insufficient authentication.",
"error_description_translated": "Insufficient authentication."
}
]
}
"""

If you could help by answering these two questions I would appreciate it:

• Have there been any changes to the authentication methods after this date?
• How should I modify existing integrations to successfully authenticate going forward?