Open Cleverbees on your computer and sign in as usual.
On the old admin site, find the Newsite link (top navigation).
Right-click it → Copy link address, and paste it above.
That link stays valid for about 90 days, so you rarely repeat this.
Use your own Cleverbees account so marks carry your name. Your login stays on this device until Cleverbees expires or revokes it (typically about 90 days). The proxy forwards your token to Cleverbees and never saves it.