Cannot add webhooks in version 12 rooms

[Ancurio]

The bot keeps replying

Failed to handle command: You must be able to set state in a room ('Change settings') in order to set up new integrations.

no matter how high I set its powerlevel. When testing in a v10 room instead, everything works as expected.

[Half-Shot]

Failed to handle command: You must be able to set state in a room ('Change settings') in order to set up new integrations.

is directed at you. The bot thinks, perhaps erroneously that your user does not have state_default permissions.

[Ancurio]

Have you successfully run the appservice from rooms v12 so far?

[Half-Shot]

Yup, we even have a test for it https://github.com/matrix-org/matrix-hookshot/blob/main/spec/permissions.spec.ts#L129. This tests that Synapse at least works.