Pushing new employee profile pictures via the BambooHR API?

I’m trying to use the BambooHR API to update employee profile pictures through a TypeScript app. This is supposedly possible according to their documentation, however, I keep getting error 400 (Bad request) when even trying the example in their docs.

First, I made sure that my API key has the correct permissions. As an example of the code:

import bamboohr from '@api/bamboohr';

bamboohr.auth('apikey', 'x');
bamboohr.uploadEmployeePhoto({companyDomain: 'Knak', employeeId: 'placeholder'})
  .then(({ data }) => console.log(data))
  .catch(err => console.error(err));

This returns a bad request error. There is apparently no parameter in the function for the actual image data, although the implementation of the function in their API github here says that there apparently is? I’m not really sure how to go about this so any help would be much appreciated.