Unable to save data between the tests

[VitalyAdweek]

I am creating a random test email to pass through the registration
Since after the registration I need to opt in using a link from email - I am visiting another website to click on the link in inbox, which I am doing in the test #3.

My issue is that the helper function which generates the test email is called again when I am visiting the a different website - rewriting the previously created email, and I have no idea how to save it so it is not rewritten.

In the example - I am logging the generated email and it is the same in tests #1 and #2, but in test #3 it is different, since the helper function is called.

Any ideas how to keep the results of the helper function to use it across all of the tests?

const getRandomTestEmail = function() {
    return  'test' + Math.floor( Math.random() * 1000 ) + '@mailinator.com';
};
const email =  getRandomTestEmail();
describe(`Using previously generated email`, () => {
    it( '#1 logging the generated email', function() {
        cy.log( email ); //returns same email
        cy.visit( 'https://www.google.com/');
        cy.log( email ); //returns same email
    })
    it( '#2 same email is logged', function() {
        cy.log( email ); //returns same email
        cy.visit( 'https://www.google.com/');
        cy.log( email ); //returns same email
        })
    it( '#3 different email is logged', function() {
        cy.log( email ); //returns NEW email
        cy.visit( 'https://www.apple.com/');
        cy.log( email ); //returns NEW email
    })
    
})