If you have it installed as a printer, then you don;t want to use Raw Data - you want to treat it as a printer and let the driver do the translation. That means using a PrintDocument
] instead of a raw printer helper.
If you really want to use a raw helper, then you will have to start looking for info on what data the actual printer expects first, and prove you can send "printable" data in that format before you even start to code.
So Google for an operations manual (or technical if you can find one) and work out what you have to send - it probably won't be as simple as "hello world!"