Proxy O365 with Webtop

We have some remote employees who work at facilities that block access to O365. We are looking at how we may create an access portal on webtop that will proxy access to O365 as a potential workaround for them. I have simply tried creating an access portal with full patching to https://outlook.office365.us, but it redirects to the login URI and is no longer proxied. I tried changing the access portal URI to the login URI, but the page never displays the login prompt. I have been searching for articles on this but so far mostly found articles on using F5 for ADFS and IdP for O365.

Has anyone tried this before? Thanks,