OK, look, for TESTING purposes, I suggest you to do with him this scenario. Is very easy and quick.

Use any of these LNbits public instances, to create a demo account:

• https://lnvoltz.com/
• https://demo.lnbits.com/

Or create a free account on nodana.io and spin up your own LNbits instance, using your LN node as funding source Or install LNbits on your own node machine and link it to your node, but you will need to expose it to clearnet with SSL certificate.

Once you have a LNbits account (it doesn't matter on which instance):

• when you open first time the wallet on the right side panel you have the API keys drop-down. Just follow the instructions from LNbits Woocommerce plugin and link the e-shop with the LNbits instance.

• you will see that also you can add a "watch-only" wallet ID (only for onchain payments). To get that, go to LNbits instance and activate the "Onchain wallet" extension. In that extension, insert whatever XPUB from a BTC wallet you want to use for received onchain payments. Then copy the walletID and put it into LNbits Woocommerce plugin settings.
• go to LNbits instance and activate the extension "SatsPay" server. This is necessary to be able to charge payments, generating invoices in the cart using LN or onchain. No need to create any "charge", is enough to be installed. Create charges with specific amount only if you need to test payments.
• activate the "Pay Links" extension, to be able to create LNURL-pay and LN Address.
• activate the "Scrub" extension if you want to automatically withdraw the funds to an external address.

And done, now you can start testing payments directly in that e-shop. If you need more help, I am here, anytime.