To create a user in AWS IAM using the CLI (after you have configured it), use the following:

Create a user with programmatic access (access key ID and secret access key):

$ aws iam create-user \
  --user-name User_Prog_Access

Response: 
{
    "User": {
        "Path": "/",
        "UserName": "User_Prog_Access",
        "UserId": "AIDExampleUserId",
        "Arn": "arn:aws:iam::123333333:user/User_Prog_Access",
        "CreateDate": "2021-01-29T12:20:43+00:00"
    }
}

$ aws iam create-access-key \
  --user-name User_Prog_Access

Response:
{
    "AccessKey": {
        "UserName": "User_Prog_Access",
        "AccessKeyId": "AKIExampleAccessKeyID",
        "Status": "Active",
        "SecretAccessKey": "ttExampleSecretAccessKey",
        "CreateDate": "2021-01-29T12:21:22+00:00"
    }
}

And for a user with console access:

$ aws iam create-user \
  --user-name User_Console_Access

Response:
{
    "User": {
        "Path": "/",
        "UserName": "User_Console_Access",
        "UserId": "AIExampleUserId",
        "Arn": "arn:aws:iam::933323111111:user/User_Console_Access",
        "CreateDate": "2021-01-29T12:31:46+00:00"
    }
}

$ aws iam create-login-profile \
  --user-name User_Console_Access \
  --password Temp_Password4 \
  --password-reset-required

Response:
{
    "LoginProfile": {
        "UserName": "User_Console_Access",
        "CreateDate": "2021-01-29T12:35:28+00:00",
        "PasswordResetRequired": true
    }
}