Can invoices be raised both manually or on computer under it act and gst?

There are two place of business at X and Y registered under one GST number in same city. Currently billing is done manually at both premises of the organization.

Proposed is as under

At X Place to raise invoice through system; computer savy staff is available to raise the invoice

At Y Place to continue manual billing; Due to lack of computer savy staff the billing is proposed to be manual

Can we do this?