When I call Conversion API,the editor seems to be blocked

The issue is not related to the conversion request you are sending.
The Document Server does not allow using internal IP addresses by default.In order to avoid this, open /etc/onlyoffice/documentserver/default.json inside the docker container => find the parameter allowPrivateIPAddress and change its value to true

"services": {
    "CoAuthoring": {
        "request-filtering-agent" : {
            "allowPrivateIPAddress": true,
            ...
        }
    }
}

After that execute supervisorctl restart all and check if the issue persists.