Typescript error: error TS2705: An async function or method in ES5/ES3 requires the 'Promise' constructor.
As se discussed in the comment, you are running the compiler in the command line by specifying the files :
tsc filename.tsThis actually means the compiler will not take into account your tsconfig.json file, it will expect that you specify the all the settings at the command line.
If you want to use a project configuration file (aka tsocnfig.json) you must either specify it explicitly using the -p option. See here for compiler options.
tsc -p tsconfig.jsonOr if you run the compiler directly in the project dir where the tsconfig.json is located you can just run the compiler without any options and it will pick the project file named tsconfig.json in the current directory
tsc