When a text message fails to send in MaidCentral and returns a “Text Message failed to send: Authenticate” error, this means that MaidCentral is having trouble communicating with your Twilio account. This is typically an issue caused by your API keys being entered incorrectly in MaidCentral, or they may have expired. Below are the steps to fix this issue.
You can first make sure that they are entered correctly in MaidCentral by going to the Company tab > Settings > General > Integrations, and clicking the Twilio bar. You will see your API keys for Twilio.

You will also need to log into your Twilio account to find your API keys to compare to make sure they are correct. Log in to your Twilio account, go to Admin > Account Management > Keys & Credentials > API keys & Tokens. You should be able to view your API keys and verify that they are entered correctly in MaidCentral. If they are, and you are still getting this error, you can generate new API keys in Twilio and enter them into your Twilio settings in MaidCentral.
Here's Twilio's guide on how to create a new API key.
Depending on when this started, it might've caused some automated text messages to fail sending out. You might need to go into some Customer Profiles > Contacts and Notifications tab, and correct any contacts that have a black circle on them. Here's our guide with more information to help.