HOW TO ADD NEW PROVIDER:

Under your eCW program, go to "File" > "Settings" > "My Settings" > Click on Tab "My Providers" > Select dropdown "Primary Service Location" to "ALL". Should see all providers. Check the box next to ones you need to add (example Quantum)  > Click on "=>" to Add to the box on the right (make sure you do so) > Then Click "OK" > It shall ask to restart eCW, normally.

**** However, *** if you get an error pop up (like below) that ask to "Please select payment method". Here is how to resolve the issue.

Under the same "My Settings". Click on tab "Defaults". [See Below] There is a line item that reads "Default Payment Method in Co-pay Screen". If you got an error, the radio box is checked under "Other", make sure to switch to "Cash" instead. Then Click "OK".  Afterward, you can go back to add providers as shown above. Shouldn't have any more issues. Thanks.