CodeIgniter 4 Shield - how to override login error message

Hello,
I would like to override the message "Unable to log you in. Please check your password." in the Shield login form. Please don't tell me use your own Validation file" etc. I know how to override other error messages ( wrong email for example ), but I do not know how to override this one. I don't know what to put in the errors array for this error message to work as a override of the original message. 
Thanks.

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