Installation document for Request Quote when Product Zero Price
Unzip downloaded package and choose exact folder for your Opencart version.
Check folder (admin, catalog, image, vqmod) with your Opencart root shop as image 1.
Upload above folders (inside folder Upload to root shop) to your Opencart root directory.
2. Add permission
Login to your Opencart admin and go to System ➔ Users ➔ User Group.
Click edit your user group name (Opencart default user group name is Administrator as Image 2.1).
Check both Access permission, Modify permission for Request Quote Product Zero Price as image 2.2.
Go to Extensions ➔ Modules ➔ Click install Request Quote Product Zero Price as image 3.
Change Status into Enable and edit another settings as image 4.1.
There are 3 optional types or all products selection for you.
You can combine one or both three types and exclude more popular products you need to show the price.