Yes, it is possible.
Log in to your account and click on "Manage Subscription".
To add a new product:
1. Go to the "Subscription" tab and click on the "Add a product" button.

2. Search for the product you want to add.
3. Select "Subscribe and Save" to add the product to your subscription or "One-time Purchase" if you only want to receive it once, during your next delivery. Then choose the delivery options associated with it.

4. Finally, click on the "Add Product" button at the bottom of the page. Your new product is now added to your subscription or your next delivery depending on the option you selected.
To modify a product (frequency, quantity, delivery date...):
1. Go to the "Upcoming Orders" or "subscriptions" tab and click on the "Modify" button.
2. Click on the product you wish to modify.

3. Choose the new options for the product.
