Appservice authorization in synapse 1.90.0 and above. Unable to send from Matrix to Discord

see https://matrix-org.github.io/synapse/latest/upgrade#app-service-query-parameter-authorization-is-now-a-configuration-option

mx-puppet-discord is no longer able to bridge messages from Matrix to Discord.

But if you enable compatibility, it still works:

use_appservice_legacy_authorization: true