Don’t want to start with a bug report, so first: Hooray for the extensions platform!!
But then: I downloaded and installed the Send to Apps extension in order to try sending content to DevonThink. However, the extension doesn’t list the apps installed on my system. For instance, DevonThink is not shown as a choice in the list of apps, but Ulysses (not installed on my machine) is. M1 MBA running Monterey