What languages are supported with amplify custom resrouce?

To add custom resources , here is the list of supported frameworks.

https://docs.aws.amazon.com/cdk/api/v1/docs/custom-resources-readme.html

But here is an example for typescript

"The AWS Cloud Development Kit (AWS CDK) is an open source software development framework to define your cloud application resources using familiar programming languages, such as Typescript"

https://docs.amplify.aws/cli/custom/cdk/