DOS, unlike Windows, has no default printer drivers. FP DOS, provided a set of printers with their 'control characters' that you could use in the FPD's report writer. If you write your report using @SAY, or ?? ... commands, then you'll need to supply the control characters to set the report characterisics.
Since FPD was last updated in July of 1994, there aren't many 'current' printers defined. If you installed the complete FPD 2.6, then go to \GOODIES\PDRIVERS. You just need to update the P_CODES.DBF and rebuild the GENPD.APP. You'll obviously also need all the printer dependent information, which the specific printer documentation (or manufacturer) should be able to supply.
Rick