[service] [request]: describe request here

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**Tell us about your request**
What do you want us to build?

Use EC2 as external instance of ECS in order to test ECS Anywhere?

**Which service(s) is this request for?**
ECS Anywhere

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**
What outcome are you trying to achieve, ultimately, and why is it hard/impossible to do right now? What is the impact of not having this problem solved? The more details you can provide, the better we'll be able to understand and solve the problem.

We would like to do proof of concept of ECS Anywhere. Before we setup servers to be used as external instances of ECS out of AWS, we would to use EC2 as external instances. However, after the EC2 instances was registered with ECS by using "Register external instances" button, the "External instance" field is shown "false". Then the task with task definition of "External" launch type cannot be launched.

**Are you currently working around this issue?**
Yes
How are you currently solving this problem?
No solution yet.

**Additional context**
Anything else we should know?

**Attachments**
If you think you might have additional information that you'd like to include via an attachment, please do - we'll take a look. (Remember to remove any personally-identifiable information.)