In the Pebble app, open the settings of your Index 01 and tap Webhook. Under it you see "Not Linked".
Paste the address into Webhook URL.
Under What to send, choose Recording. This is the fastest choice, and the only one that sends every recording: Both waits for the phone's own transcription first, and sends nothing when the phone hears no speech.
Leave Headers empty and leave Sign requests off.
Tap Save, then tap Send test event. Keep this page open: it tells you when the test arrives.
Go back and tap Ring Button. For Hold & Talk, choose Webhook only. If you want to keep what the button does today, keep it and turn on Also send to webhook.
Hold the ring's button with its microphone hole pointing up and out, 5 to 10 cm from your mouth, and keep your finger off the hole. Say Begin transcript in your normal voice, and nothing else, then let go. That first recording becomes your voice sample: Stemme puts it in front of each recording, so it hears you better. This page tells you when the recording arrives.