The current https://protonvpn.com/what-is-my-ip-address website is convenient in order to find out my device's public IPv4 address. However, the way it is coded, the address is displayed using javascript (default 127.0.0.1). This makes it impossible to use curl from a script to find out the device's public IPv4 address. As a result, scripts have to use other websites. There are many that offer this, but it's not very private.

For those of us who need an algorithmic way to find out IPv4 address using a script, it would be nice if Proton offered this same capability. For example, https://ifconfig.me/ can be used by parsing the HTML output to find the IPv4 address. Better is https://ipv4.icanhazip.com, but this also has privacy issues.

Of course, the site should be rate limited, to prevent overload. My script usually checks every 30 minutes.

Another approach would be to only serve the IPv4 address when presented with an OAuth token, which could be created by a logged in user on the protonvpn.com website. Even if this expires , say, on a yearly basis, I would not mind updating my script occasionally to use a newer token.