Delay using Promise.all() in a for - promise

Question

I need to add a delay when executing each promises in Promise.all().
My code :
for (let i = 0; i < stockDiff; i++) {
var invoiceObject = {
sellProducts: [{
quantity: 1,
description: '<p style="margin: 0;">' + findedProduct.name + '</p>',
digital_access: findedProduct.digital_access,
forced_ttc_price: parseFloat(findedProduct.ttc_price, 10),
offer_amount: null
}],
totalHt: findedProduct.ht_price,
totalTtc: findedProduct.ttc_price
};
promises.push(InvoiceController.createInvoice('À la commande', null, null, 2, null, null, null, null, null, null, invoiceObject.sellProducts));
}
Promise.all(promises).then(function() {
request.flash('success', 'Stock mis à jour !');
response.redirect('/product/_index');
});
My function InvoiceController.createInvoice() returns a promise :
function createInvoice(rule, publicNote, privateNote, state, customerId, userId, address, complementaryAddress, postalCode, city, products, services, productPackages) {
var productsPromise, servicesPromise, productPackagesPromise,
promises = [];
return InvoiceModel.create({
date: new Date(),
rule: rule,
public_note: publicNote,
private_note: privateNote,
state: 1,
address: address,
complementary_address: complementaryAddress,
postal_code: postalCode,
city: city,
customerId: customerId,
userId: userId
}).then(function(createdInvoice) {
if (products) {
productsPromise = _.map(products, function(product) {
return InvoiceProductModel.create({
invoiceId: createdInvoice.id,
quantity: product.quantity,
description: product.description,
forced_ttc_price: product.forced_ttc_price,
offer_amount: product.offer_amount
});
});
}
if (services) {
servicesPromise = _.map(services, function(service) {
return InvoiceServiceModel.create({
invoiceId: createdInvoice.id,
quantity: service.quantity,
description: service.description,
forced_ttc_price: service.forced_ttc_price,
offer_amount: service.offer_amount,
start: service.start,
end: service.end
});
});
}
if (productPackages) {
productPackagesPromise = _.map(productPackages, function(productPackage) {
return InvoiceServiceModel.create({
invoiceId: createdInvoice.id,
description: productPackage.description,
forced_ttc_price: productPackage.forced_ttc_price,
offer_amount: productPackage.offer_amount,
start: productPackage.start,
end: productPackage.end
});
});
}
promises = _.flattenDeep(productsPromise.concat(servicesPromise).concat(productPackagesPromise));
return Promise.all(promises).then(function() {
return createdInvoice.update({
state: state
}).then(function(updatedInvoice) {
return Promise.resolve(updatedInvoice);
});
});
});
}