Create a https endpoint with RunKit / Vercel or any platform, which returns a JSON in this format:
{
    subject: 'hello',
    status: 'world',
    color: 'blue'
}
Assume the endpoint can be reached as:
https://some-endpoint.example.com/what/ever/args
then the corresponding badge url on Badgen is:
/https/some-endpoint.example.com/what/ever/args
Take this endpoint & badgen url for example:
Furthermore, you may append path args to it:
/https/:hostname/:pathname*