To send stream to Castr from LiveU Solo, you can follow this guide.
To get the API key, simply reach out to our team via chat. We will assist you in obtaining the key for LiveU integration with Castr, and you can expect to receive it within 48 hours.
To get constant pull URLs, you can follow these guides:
RTMP: guide link
SRT: guide link
If you are facing issue with connect via SRT, you can check this guide.