Hey!
I'd definitely agree with other forum users - if there isn't a separate extracurriculars section or questions that ask for it, it's perfectly fine to include them in the work experience section.
However, I would limit this to extra-curriculars that are 'structured' (i.e. not hobbies) such as university societies, sports clubs, or volunteering. This is because you will expected to outline the role, responsibilities and skills that you gained within the work experience entry, and this may be more difficult for some hobbies