AWS Lambda deployment && "SyntaxError: Unexpected token '<'"

[setevoy2]

Description

The deployment guide about AWS Lambda is incomplete and it's hard to realize how to run the code.
After eventually ran it, got the error saying:

{
"errorType": "Runtime.UserCodeSyntaxError",
"errorMessage": "SyntaxError: Unexpected token '<'",
"stack": [
"Runtime.UserCodeSyntaxError: SyntaxError: Unexpected token '<'",
" at _loadUserApp (/var/runtime/UserFunction.js:98:13)",
" at Object.module.exports.load (/var/runtime/UserFunction.js:140:17)",
" at Object. (/var/runtime/index.js:43:30)",
" at Module._compile (internal/modules/cjs/loader.js:1072:14)",
" at Object.Module._extensions..js (internal/modules/cjs/loader.js:1101:10)",
" at Module.load (internal/modules/cjs/loader.js:937:32)",
" at Function.Module._load (internal/modules/cjs/loader.js:778:12)",
" at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:76:12)",
" at internal/main/run_main_module.js:17:47"
]
}

Provide a clear and concise description of the issue, including what you expected to happen.

Reproduction

As there is no defined Handler in the docs, I did the following:

1. cloned the repository to my local machine from the Releases page (3.10, latest)
2. ran the npm install to install packages (as previously got the "Runtime.ImportModuleError: Error: Cannot find module '@octokit/rest'" error)
3. created a zip-archive with the node_modules included and uploaded it to an AWS Lambda function
4. added an API Gateway

Now, when creating a PR in a Github repository, it fails with the 500 error and the function's CloudWatch logs days about the "SyntaxError" error.

Environment

Runtime: Node.js 14.x (the same issue when using 10.x which is mentioned in the docs)
Handler: src.index.lambda