Access the dashboard from the internet without opening ports

Good morning,

I'm trying to do one thing, but I don't know how to approach it or how to do it.
I have multiple systems with Node-Red + Dashboard. I have to be able to control it from the internet. In some of them, with a DDNS and opening the ports in the router I can access, but there are several of them in which I cannot open ports because I do not have access to the router.

Thinking, the only thing that has occurred to me that it could still work, would be a VPS with a VPN server and reverse proxy, that the raspberry where the node network is connected automatically and to be able to access.

I have read other solutions like putting node network in a vps and sending by mqtt to make a mirror, but in this case it is not viable. Any help on how I could do it?

Thank you!!

Zero tier is a very nice free option to get remote access to your local network.
Setting it up is easier then port forwarding.