If you login, you can test how sending message work.
Once logged in, you will have DEMO account with API document to test the same.
The minimum purchase is 4000 credits . Then, you can keep making the recharges that you need.
You can send text,excel,word, image (png & jpg), videos audio (ogg), pdf and emojis. Furthermore, you can send links to other ﬁles, videos etc.
Yes, with hyperlinks you can attach any type of content
Yes. All messages are sent directly from your own number. You can see the sent message details on your whats app.
Your credit has expiration date as per your plan purchase terms.
Yes, of course ;)