it can be done passing bookingInfo prop as in below code

const nylasScheduling = document.querySelector('nylas-scheduling');
              
nylasScheduling.clientId = NYLAS_CLIENT_ID;
nylasScheduling.slug = schedulePageName;

nylasScheduling.bookingInfo = {
    primaryParticipant: { name : 'maaz qureshi', email: '[email protected]'}
};