Yes. Typically you'll need to use your computer/phone connected to your OpenWrt device (which is in turn connected to the hotel wifi) in order to access and submit through the captive portal.
https://openwrt.org/docs/guide-user/network/wifi/connect_client_wifi
There's also a package called travelmate which is designed for this type of application:
Hi,
in the OpenWrt stable & snapshot package repo you'll find the travelmate package, a wlan connection manager for travel router.
Main Features
STA interfaces operating in an "always off" mode, to make sure that the AP is always accessible
Easy setup within normal OpenWrt environment
Strong LuCI-Support with builtin interface wizard and wireless connection manager
Fast uplink connections
Support all kinds of uplinks, incl. hidden and enterprise uplinks
WPA3 support
includes a vpn hook with …