Unable to use 'service-role/xxx' when calling `createActivation`

I use aws-sdk-js to create activation, here is the code:

const AWS = require('aws-sdk');
const ssm = getSSM({ region: 'us-east-1' });
ssm.createActivation({
  IamRole: 'service-role/AmazonEC2RunCommandRoleForManagedInstances'
}, (...args) => console.log(args));

And I got the following error:

{ ValidationException: 1 validation error detected: Value 'service-role/AmazonEC2RunCommandRoleForManagedInstances' at 'iamRole' failed to satisfy constraint: Member must satisfy regular expression pattern: ^[\p{L}\p{N}+=,.@\-_]*$
      at Request.extractError (/tetrascience/ts-service-datahub/node_modules/aws-sdk/lib/protocol/json.js:51:27)
      at Request.callListeners (/tetrascience/ts-service-datahub/node_modules/aws-sdk/lib/sequential_executor.js:106:20)
      at Request.emit (/tetrascience/ts-service-datahub/node_modules/aws-sdk/lib/sequential_executor.js:78:10)
      at Request.emit (/tetrascience/ts-service-datahub/node_modules/aws-sdk/lib/request.js:683:14)
      at Request.transition (/tetrascience/ts-service-datahub/node_modules/aws-sdk/lib/request.js:22:10)
      at AcceptorStateMachine.runTo (/tetrascience/ts-service-datahub/node_modules/aws-sdk/lib/state_machine.js:14:12)
      at /tetrascience/ts-service-datahub/node_modules/aws-sdk/lib/state_machine.js:26:10
      at Request.<anonymous> (/tetrascience/ts-service-datahub/node_modules/aws-sdk/lib/request.js:38:9)
      at Request.<anonymous> (/tetrascience/ts-service-datahub/node_modules/aws-sdk/lib/request.js:685:12)
      at Request.callListeners (/tetrascience/ts-service-datahub/node_modules/aws-sdk/lib/sequential_executor.js:116:18)
    message:
     '1 validation error detected: Value \'service-role/AmazonEC2RunCommandRoleForManagedInstances\' at \'iamRole\' failed to satisfy constraint: Member must satisfy regular expression pattern: ^[\\p{L}\\p{N}+=,.@\\-_]*$',
    code: 'ValidationException',
    time: 2019-06-28T15:12:53.630Z,
    requestId: '4f10020c-8acd-470c-ade3-89d2046bb07c',
    statusCode: 400,
    retryable: false,
    retryDelay: 4.082470922819459 }

I created an issue at aws-sdk-js repo: https://github.com/aws/aws-sdk-js/issues/2748 , and I was told that the regex validation error comes from the server side.

Based on the reference of AWS SSM API, there is no regex pattern constraint on the IamRole parameter. (https://docs.aws.amazon.com/systems-manager/latest/APIReference/API_CreateActivation.html) Why does the server returns a regex error?