How can I use random string in cypress test

How can I use random string in my cypress test so that whenever my gitlab-runner runs the code, the system will use difference strings like the Email and Phone number majorly.

I have my class created which i do call in my script.

here is the class that i created .

export class SignupPage{
   
 enterFirstname(firstname){
        cy.get('.grid-cols-2 > :nth-child(1) > .relative > .w-full').type (firstname)
    }
    enterlastname(lastname){
        cy.get('.grid-cols-2 > :nth-child(2) > .relative > .w-full').type(lastname)
        }
    
    enterEmail(email){
        cy.get('.space-y-3 > :nth-child(2) > .relative > .w-full').type(email)
      }
        enterBusinessName(businessName){
        cy.get(':nth-child(3) > .relative > .w-full').type(businessName)
        }
    enterBusinessType(){
    cy.get('#headlessui-listbox-button-1').click()
cy.get('#headlessui-listbox-option-4 > .font-normal').click()
}
    enterPhoneNumber(phoneNumber){
        cy.get(':nth-child(5) > .relative > .w-full').type(phoneNumber)
    }
    enterPassword(password){
        cy.get(':nth-child(6) > :nth-child(1) > .relative > .w-full').type(password)
  }
  clickAgreementBox(){
    cy.get('.h-4').click()

  }
        clickContinue(){
            cy.contains('Continue').click()
     
        }
        }

here is my test script

import { SignupPage } from "./pages/signup_page"


    const signupPage = new SignupPage()

describe('Registration', () => {
    it ('SoftPay registration page', () =>{
        cy.viewport(1280, 720)

        function makeid(length) {
            var result           = '';
            var characters       = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
            var charactersLength = characters.length;
            for ( var i = 0; i < length; i++ ) {
               result += characters.charAt(Math.floor(Math.random() * charactersLength));
            }
            return result;
         }

        cy.visit('softpayfront.softalliance.com/')
        cy.contains('Create Account').click()

        signupPage.enterFirstname('Adunola')
        signupPage.enterlastname('Adunola')
        signupPage.enterEmail(makeid(6) + "@mailsac.com")
        signupPage.enterBusinessName('SoftPay TESTING')
        signupPage.enterBusinessType()
        signupPage.enterPhoneNumber(makeid(8)+ "82090808070")
        signupPage.enterPassword('Password#1')
        signupPage.clickAgreementBox()
        signupPage.clickContinue()
        cy.end()
      })
      

})

this only work for the random email but not for the phone number

 function makeid(length) {
            var result           = '';
            var characters       = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
            var charactersLength = characters.length;
            for ( var i = 0; i < length; i++ ) {
               result += characters.charAt(Math.floor(Math.random() * charactersLength));
            }
            return result;
         }