Med_gas_mask inventory icon

['med_gas_mask'] = {
    label = 'Med Gas Mask',
    weight = 100,
    stack = true,
    close = true,
},

Image goes in ox_inventory/web/images. Set the weight to what fits your server.

med_gas_mask = { name = 'med_gas_mask', label = 'Med Gas Mask', weight = 100, type = 'item', image = 'med_gas_mask.png', unique = false, useable = true, shouldClose = true, description = '' },

Image goes in qb-inventory/html/images. Set the weight to what fits your server.

INSERT INTO `items` (`name`, `label`, `weight`, `rare`, `can_remove`) VALUES
('med_gas_mask', 'Med Gas Mask', 1, 0, 1);

Image goes in your inventory images folder (ox_inventory/web/images on ESX Legacy). Set the weight to what fits your server.