TypeError: Cannot read property 'then' of undefined

[azrin1972]

I'm running nbrowser in Ubuntu Desktop 20
a simple injector sending the URL and an nbrowser node

upon clicking the intector my node-red exits with the following log

19 Aug 21:32:50 - [info] Starting flows
19 Aug 21:32:50 - [info] Started flows
19 Aug 21:32:50 - [info] Server now running at https://127.0.0.1:1880/
19 Aug 21:32:58 - [red] Uncaught Exception:
19 Aug 21:32:58 - TypeError: Cannot read property 'then' of undefined
    at nbrowser_worker (/usr/local/lib/node_modules/node-red-contrib-nbrowser/nbrowser/nbrowser.js:367:19)
    at Timeout._onTimeout (/usr/local/lib/node_modules/node-red-contrib-nbrowser/nbrowser/nbrowser.js:431:21)
    at listOnTimeout (internal/timers.js:531:17)
    at processTimers (internal/timers.js:475:7)

im using node version 12.4.1