regular expression about proxy

I have a local product with url: "https://local.name.test/pos/product". But the post to get the backend is blocked by cors.So I have to use proxy like lightProxy.

I need only the second url with "post" like "https://local.name.test/post/product" proxy to "https://online.name.test/post/product", the other stay in local.But I don't known how to write the regular expression.