Install dependencies:

npm install.

Copy config.js.dist to config.js.

Add accounts in config.js, for example

// ...
    accounts: [797040, 796695, 993968],
// ...

Then set the exported private key and the used password.

// ...
    key: {
        pk: 'ABCDEF....',
        pw: 'password'
    }
// ...

Run via node spam.js.