How to Track Supplier-Provided Spares for Warranty Devices?

I am using ERPNext and have suppliers who provide me with printers. Occasionally, they also provide spares at no cost, which I use for devices they have supplied that are under warranty. How can I record these transactions in ERPNext without reflecting them in the company’s accounts since they are not purchased in the company’s name? I want to track the inventory and ensure proper usage tracking without affecting the financial records. What would be the best way to configure this?

You can create purchase invoice at zero valuation rate

ok @mujeerhashmi

As referenced by @mujeerhashmi you can invoice on zero valuation rate also I suggest you to use batch for those items to be able to track those pieces and not missed up with payed ones
simply you can have warenty batch and not warenty batch

Yeah I use serial nos to track those!

But still they will effect your valuation for paid but on batch you can have batch valuation I think and that will separate valuation of non free and free pieces