QBCore instalation

1. Open config.lua and set Framework.QBCORE = true and MySQLFramework.OXMYSQL = true It should look like the following

-- if "STANDALONE" is on true, nothing under will take effect.
Framework = {
    STANDALONE = false,

    ESX = false,
    QBCORE = true,
}

-- if "DISABLE_MYSQL" is on true, nothing under will take effect.
MySQLFramework = {
    DISABLE_MYSQL = false,

    MYSQL_ASYNC = false,
    GHMATTI_MYSQL = false,
    OXMYSQL = true,
}

1. Add items in qb-core/shared/items.lua

['spray'] 	  = {['name'] = 'spray', ['label'] = 'Spray', ['weight'] = 500, ['type'] = 'item', ['image'] = 'spray.png', ['unique'] = false, ['useable'] = true, ['shouldClose'] = true, ['combinable'] = nil, ['description'] = 'Spray paint can'},
['spray_remover'] = {['name'] = 'spray_remover', ['label'] = 'Spray Remover', ['weight'] = 500, ['type'] = 'item', ['image'] = 'spray_remover.png', ['unique'] = false, ['useable'] = true, ['shouldClose'] = true, ['combinable'] = nil, ['description'] = 'Removes graffiti'},

1. Add item images from rcore_spray/inventory_images to qb-inventory/html/images/

2. Start the script, wait 5 seconds and restart your server (to load newly added items)