SMS - Images Not Sent - Error: Method not implemented

We are using the Twilio API to send text messages. Regular SMS works fine, but when we attempt to send an image (have attempted small and large PNG and JPEGs), nothing is sent and the logs show:

{"level":50,"time":"2023-08-20T01:19:08.910Z","pid":1,"hostname":"c9bb1f9b-748e-4c62-94f5-033b95106ad0","name":"[Omnichannel] Callback","err":{"type":"Error","message":"Method not implemented.","stack":"Error: Method not implemented.<br> at Twilio.fileUploadMediaTypeWhiteList (server/services/omnichannel-integrations/providers/twilio.ts:185:9)<br> at server/services/omnichannel-integrations/providers/twilio.ts:151:56<br> at /app/code/bundle/programs/server/npm/node_modules/meteor/promise/node_modules/meteor-promise/fiber_pool.js:43:40<br> => awaited here:<br> at Function.Promise.await (/app/code/bundle/programs/server/npm/node_modules/meteor/promise/node_modules/meteor-promise/promise_server.js:56:12)<br> at app/livechat/server/sendMessageBySMS.ts:71:4<br> at /app/code/bundle/programs/server/npm/node_modules/meteor/promise/node_modules/meteor-promise/fiber_pool.js:43:40"},"msg":"Method not implemented."}

We have "File Uploads Enabled" checked under Settings > SMS and Settings > Omnichannel. This is a brand new server with the latest RC via Cloudron.

Start with server/services/omnichannel-integrations/providers/twilio.ts, especially fileUploadMediaTypeWhiteList at line 185 and its call around line 151. Then read app/livechat/server/sendMessageBySMS.ts around line 71 to trace image sending. Done means image SMS requests no longer fail with “Method not implemented” when file uploads are enabled.