Csn the system give line level or item-wise discounts. I checked on the gear icon and it only allows me to enable discount below the invoice

It's nice to see you here in the Community, hannes-o.

I can help you create item-wise discounts in QuickBooks Online.

Offering discounts to your customers is a great business idea. However, the option to enable the item-wise discount is currently unavailable in QuickBooks Online.

As a workaround, you can create a service item for the discount. Below are the steps to complete the process.

1. Select Settings ⚙ and then Products and Services.
2. Select New to create a new item.
3. Select Non-inventory or Service for the type.
4. Name the item Discount. If you want to create multiple discount items, give them unique names so they're easy to tell apart.
5. In the Sales price/rate field, enter the discount as a negative amount. Keep in mind, this is a dollar amount and not a percentage.
6. From the Income account drop-down menu, select the Discount given account. QuickBooks creates this account for you when you turn on the discount feature.
7. Select Non-taxable under the Sales tax category drop-down.
8. When you’re done, select Save and close.

Once done, you can add the discount item to an invoice.

1. Select the + New button.
2. Select Invoice.
3. Select a customer.
4. Add a PRODUCT/SERVICE, QTY, RATE, and AMOUNT.
5. In the next line, select the discount item.
6. Enter the discount price in the RATE column. Let's make sure that it's in a negative form.
7. Click Save and close.

I'm leaving you this article: Add product and service items to QuickBooks Online. This will give you steps on how to edit an item as well as ways in managing them in QuickBooks Online. Also, you can get the detailed steps in deleting and reactivating an item in QuickBooks.

You can always leave a message if you have any questions. I'll be happy to answer them for you. Have a good one.