Pi-hole is intended to be deployed on a trusted network containing trusted computers and devices. It shouldn't be exposed to the Internet, as a way to reach it when away from your network, as it will be found and quickly abused to cause problems for others.
To access your Pi-hole while away you can use a VPN to send all DNS privately back to your trusted network, eg take a look at the Pi-hole WireGuard guide. Alternatively you can create a small travel Pi-hole, which is handy if you want to use other networks or if you have family in a car who want to go online.
I guess you could install it on a travel laptop, with the caveat that it needs to be available all the time, so the laptop would either need to be running a supported OS or else a small VM which would need to stay fired up.