The password comes from Active Directory. On the user object in Active Directory Users and Computers, click the checkbox to not let the password expire.
From the notes, I understand that you want to disable the password expiration. Here are steps to follow to achieve that:
 Launch an EC2 Windows Instance.
 Domain join it to your Directory (This will enable you to login in as an Administrator)
 Connect to your instance.
 You can now change/reset your password policies.
I have included a link  to guide on Supported Policy Settings available to achieve the above mentioned issue.
Manage password policies for AWS Managed Microsoft AD https://docs.aws.amazon.com/directoryservice/latest/admin-guide/ms_ad_password_policies.html
Disabling password expirationasked 2 months ago
SES SMTP Password Lengthasked 2 months ago
Lambda Deployment - Do you have to set the TargetVersion?asked 5 months ago
How can I set up Collision Lozenges for a character in EMotionFX?Accepted Answerasked 5 years ago
Is possible to set up the BGP pass on a S2S VPN connectionAccepted Answerasked 4 months ago
Re-set password sever errorasked 4 months ago
I have a DNS problem with one domainAccepted Answerasked 3 years ago
Logging into SDK in Visual Studio using a different machineasked 3 years ago
HOW TO set up the required IAM permissions for WorkMail??asked 8 months ago
Adding a User to Simple AD Directory in Workspaces - AWS CLIasked 3 years ago