const body = new URLSearchParams({
sheetName: 'Лист1',
cell: 'E2',
newValue: 'Новое значение'
}).toString();

fetch('https://script.google.com/macros/s/скрыто/exec', {
method: 'POST',
mode: 'no-cors',
body: body,
credentials: 'include',
headers: {
'Content-Type': 'application/x-www-form-urlencoded'
}
})