The url generated isn't valid according to curl:
curl -v 'https://echoserver.dev/server?query={"headers":[["foo","bar"]],"body":{"type":"text","data":"asdasdasadsasdasd"},"status":200}'
curl: (3) nested brace in URL position 48:
https://echoserver.dev/server?query={"headers":[["foo","bar"]],"body":{"type":"text","data":"asdasdasadsasdasd"},"status":200}
CF-Cache-Status: DYNAMIC CF-Ray: 7cacf9735d5c7373-CPH Connection: keep-alive Date: Sun, 21 May 2023 12:55:33 GMT Server: cloudflare Set-Cookie: __cf_bm=cAVNRtth0_6tpGLa8p2wbe6EuPRO2ZKITru5y9_GYgE-1684673733-0-AUMvqDbcxAHGRLPD2ghFL+6yJ0RKm0kGPtzsiU4jFChGrB02xtkPe8I2OX6+kFApwcWiEI1p+mFNA+esRO58cVI=; path=/; expires=Sun, 21-May-23 13:25:33 GMT; domain=.echoserver.dev; HttpOnly; Secure; SameSite=None Set-Cookie: _cfuvid=wP9ezST2Ks4reP.MMtYKTxisnCjBHSGc65SDqhRDdCU-1684673733888-0-604800000; path=/; domain=.echoserver.dev; HttpOnly; Secure; SameSite=None Transfer-Encoding: chunked Vary: Accept-Encoding alt-svc: h3=":443"; ma=86400, h3-29=":443"; ma=86400 x-render-origin-server: Render