Why can I not get any text to appear from my function in my contect-processor.py to work?

PROJECT
  -|project
  -|careers
     -|models.py
     -|context_processor.py
     -|templates
        -|template.html
      

context_processors.py

from .models import Careers

def careers_exist(request):
    # Check if there are any active careers
    careers_available = Careers.objects.filter(active=True).exists()
    
    # Prepare the context dictionary based on availability
    if careers_available:
        header = {'header': 'Current vacancies'}
    else:
        header = {'header': 'No Vacancies'}
    
    return {'header' : header}

template.html

<h2>{{ header.header }}</h2>

Why is my template still blank despite doing everything correctly.