If you are not getting printed on the physical invoices,even though e-invoicing is enbaled,to enable it you can follow given steps:
Step 1:Go to the Administration menu,
Step 2:Click on configuration,
Step 3:Click on Invoice/Document Prinitng,
Step 4:Click on standard and sale invoice,
Step 5:Here you can find an option is Print E-Invoice QR code and Print E-Invoice IRN/ACK No./ACK Date,enable it here, then save this window.
Now when you generate an e-invoice in BUSY, it will display the E-invoice QR code and IRN number in the printout.