I need to send whatsapp messages with text and attached pdf files. is it possible from windows desktop app?
You might have to use Twilio.
Paul Lefebvre has an example of using Twilio from Xojo here:
Twilio has an API for WhatsApp which I’d expect works similarly to the SMS api Paul’s referencing in his example. Details on the API are here:
from xojo i think the idea was paid whatsapp business api. could be expensive.
without xojo whatsapp desktop app or
this whatsapp running in browser which can be linked via qr code.