I am by no means a tax expert but based on the publicly available information the way I am understanding the CRA page for the place of supply rules determines whether GST or HST should be charged and makes no mention of PST.
In the case of BC, the place of supply is the delivery address meaning GST should be applicable since we don't have HST.
https://www.canada.ca/en/revenue-ag...t-businesses/charge-collect-place-supply.html
According to the BC Bulletin on PST, there is a section that mentions businesses outside BC and when they need to collect PST.
https://www2.gov.bc.ca/assets/gov/t...ations/pst-001-registering-to-collect-pst.pdf
Businesses Located Outside B.C. but Within Canada
You must register to collect and remit PST if you are located outside B.C. (see Location of Your Business below) but within Canada and do
all of the following in the ordinary course of your business:
Sell taxable goods to customers in B.C.
Accept orders from customers located in B.C. (including by telephone, mail, email or Internet) to purchase goods
Deliver the goods you sell to your B.C. customers to locations in B.C. (this includes goods you deliver through a third party, such as a courier)
Solicit persons in B.C. (through advertising or other means, including mail, email, fax, newspaper or the Internet) for orders to purchase goods
Note: If you have only a website that is accessible from anywhere in the world, which does not target B.C. customers, you are not soliciting sales in B.C. However, if you have a website and also solicit sales in B.C. by other means, such as through targeted internet advertisements, promotional flyers or newspaper advertisements, you are soliciting sales in B.C.
If you meet these criteria, you must be registered before delivering goods into B.C., providing software for use on or with an electronic device ordinarily situated in B.C., or providing telecommunication services.
Marketplace Facilitators and Marketplace Sellers
A marketplace facilitator is a person who:
operates, owns or controls (solely or jointly) an online marketplace,
through the online marketplace, facilitates a marketplace seller’s retail sale or lease of goods, sale of software or sale of related services, accommodation, telecommunication services or online marketplace services, and
collects payment in respect of that retail sale or lease. Generally, if you are a marketplace facilitator located in or outside B.C., you must
register to collect and remit PST on the sales and leases you facilitate in B.C., and on the online marketplace services you sell or provide in B.C.
So i guess if Western Metals is online only then they need to collect PST
But if they have a business that is brick and mortar and doesn't target BC customers then they dont need to collect PST