TS2705
An async function or method in ES5/ES3 requires the 'Promise' constructor. Make sure you have a declaration for the 'Promise' constructor or include 'ES2015' in your '--lib' option.
Solution:
Include the ES2015 library in the --lib option of your tsconfig.json :
{
"compilerOptions": {
"target": "ES5",
"lib": ["ES5", "ES2015"] // Include ES2015 for Promise support
}
}