Need Help With Word Press and BTCPay Server

Hey all,

I’m starting a Bitcoin club at my university and building a website to sell club merch. The issue is I’m not very tech savvy and can’t figure out how to link WooCommerce and the BTCPay Server hosted on my Umbrel.

I don’t know what to put for my BTCPay URL because I manage Umbrel and the BTCPay Server remotely through TOR. Therefore, I don’t have a clear web address. Here is an image for reference.

Am I missing something obvious here? Thank you!