The first step is to get a collections paybill from Safaricom if you don't have a paybill; and you can get one by walking into any Safaricom shop, or apply online
After getting the paybill, you need to get access to their Mpesa portal. Usually Safaricom will give them access, but it is not the case for all. If you are not given access to the portal then write an email to: M-PESABusiness@safaricom.co.ke and request for a business administrator to be created on your paybill, learn how to do that from here.
Once you have access to the Mpesa portal, log in and create for us an API operator/user share with us the credentials (the API operator's username and password). Learn more about that here.
Have further questions, reach out to us: firstname.lastname@example.org