How to consume a spring boot api containing #CurrentUser annotation with react? - reactjs

Question

I'm trying to consume a Spring-Boot API using React.
It worked fine on the server side and lately I had to add #CurrentUser UserPrincipal userPrincipal as a parameter and it's still working fine.
The problem is when trying to send Http requests it starts giving me a NullPointerException and I expected that because I didn't add anything inside the react function.
What must I add in the frontend?
Backend:
#CrossOrigin(origins = "*", maxAge = 3600)
#PostMapping("/FileUpload")
public void fileUpload(#RequestParam("file") MultipartFile file, #CurrentUser UserPrincipal userPrincipal,
Patient patient, Observation observation) {
String result = hl7v22cs.fileParser(file);
if (result.contains("|2.2")) {
hl7v22cs.fileParser(file);
hl7v22cs.textParser(file);
hl7v22cs.extractPatientSegment(userPrincipal, patient, file);
hl7v22cs.extractObservationSegment(observation, file);
}
}
Frontend:
class ConverterService {
convert(file) {
let formData = new FormData();
formData.append("file", file);
return axios.post("http://localhost:8080/api/FileUpload", formData, {
headers: {
"Content-Type": "multipart/form-data",
}
});
}
}