Sending invoice from mobile device

[lawill_16]

I sell on eBay from my phone.  I have customers that purchase more than 1 item and want to be invoiced for combined shipping but I can not figure out how to do that from my phone.  

[lawill_16]

Also,  when I try to issue a refund from my phone a prompt comes up that says:

!user is not enrolled in managed payments 

so I can’t even refund the difference