How to intercept a networkrequest and check its requestHeaders with Cypress

I am working with Cypress and I am testing the FrontEnd.

I would like to check the requestHeaders of the following networkcall. The call is already been intercepted and stubbed namely AssessmentStub:

From the browserDevTools you can see following: I want to assert the x-classification and its value that you can find in the request Headers.

This call is a GET call requested by the webaplication. I am testing the UI and want to check if it is requesting the correct x-classification in the request Header.

The code looks like the following now, but it is not working:

       it.only('Is the Frontend requesting the correct API-Endpoint after changing the Classification', () => {
    cy.get('app-assessment-tests-header > app-classification-selector').click()
    cy.intercept('GET', '**/api/assessmenttestreference').as('AssesmentStub')

    cy.get('.popup').contains('HAVO').click()

    cy.get('@AssesmentStub').then((request) => {
        expect(Request.Headers).to.have.property('x-classification', 'f0651c9a-649b-4217-a85f-ce5c79f0d773')
    })

});

You can try this:

cy.wait('@AssesmentStub')
  .its('request.headers')
  .should(
    'have.property',
    'x-classification',
    'f0651c9a-649b-4217-a85f-ce5c79f0d773'
  )