Autopopulate/Autofill field based on selected value on first field

Hello, I am trying to make another field automatically populated (without selecting on dropdown as the dynamic select lookup does) based on the selected field value on a first field.
Example: I have Item_tbl with fields item_
id, item_sku and item_name. order_tbl with fields order_itemid, order_itemsku and order_itemname.
In order_tbl, order_itemsku is a lookup field from Item_tbl.item_sku. I am trying to utilize the Autofillinput to automatically populate the order_itemname based on the user selected value on order_itemsku but no luck. The goal is to automatically input the related field in the order_itemname based on the user selected input in order_item sku (without having to click on the dropdown on order_itemname because it should be a text value and disabled so the user doesn’t need to worry about) and must update if the user change the value.

you may check this thread: