Cart - Use permalinks to pre-load the cart

Worked a treat, thanks @Jesse_Meyers - so issue is, how did you end up with completely different product IDs - where do I find these?

EDIT: Looks like it’s because of variant IDs?

What would I do for this site, which has a subscription (and no variants?)…

https://corgimodelclub.com/

The subscription product on home page.

Thanks again!