Custom zero trust tunnel with Shopify Remix app template

Hi,

Using the Shopify remix app template, I’ve found the default free cloudflare tunnels to be very flaky, so i’ve created a cloudflare account to use my own zero trust tunnels that i’m hoping will be less flaky.
Does anyone know how i would use my own tunnel(s) with the remix app template?

I know there is a --tunnel-url parameter -

npm run dev --reset  -- --tunnel-url <tunnel>

but i’m just not sure what i should be specifying here. Nothing i’m trying seems to be working. Also, doesn’t the remix app template expose more that one port? and if so, how does that work when only specifying 1 tunnel url?

I don’t mind trying to figure this out myself if anyone knows where the documentation is for this… but i can’t seem to find anything anywhere. Thanks for your help.