trouble with newly composer installed API

I installed with composer. But I think something went wrong. I did get a popup about using an older version of composer. When I run it I am getting this error:
Class 'Sendpulse\RestApi\ApiClient' not found
at this line
$SPApiClient = new ApiClient(API_USER_ID, API_SECRET, new FileStorage());

I am including these lines in the top of my module:
use Sendpulse\RestApi\ApiClient;
use Sendpulse\RestApi\Storage\FileStorage;

I took a look but I  do not find Sendpulse installed in my Vendor directory  at all, like the other packages I am using. 

What to do?

proof that an old dog can learn new tricks

This is absolutely not a Codeigniter related issue. You should go back to the API reference docs and read the docs clearly.

thanks. This forum states "Programming questions? Not sure where else to ask something?" in it's subtitle.

I am not sure where else to "ask something". Seems fitting to me.

proof that an old dog can learn new tricks