It wasn't clear, but eventually I found: https://doc.livehelperchat.com/docs/canned/ -- I made sure "'lhchat', 'explorecannedmsg'" permissions were enabled, but that didn't seem to help.
]]>[== Undefined ==]
853a6cc8fc98e3350d02c9f99195b422.js:2495 TypeError: c.map is not a function
at CannedMessages.js:127:14
at is (853a6cc8fc98e3350d02c9f99195b422.js:2495:84464)
at gl (853a6cc8fc98e3350d02c9f99195b422.js:2495:103262)
at t.unstable_runWithPriority (853a6cc8fc98e3350d02c9f99195b422.js:2495:129315)
at Ur (853a6cc8fc98e3350d02c9f99195b422.js:2495:46356)
at pl (853a6cc8fc98e3350d02c9f99195b422.js:2495:103021)
at Gs (853a6cc8fc98e3350d02c9f99195b422.js:2495:94797)
at 853a6cc8fc98e3350d02c9f99195b422.js:2495:46647
at t.unstable_runWithPriority (853a6cc8fc98e3350d02c9f99195b422.js:2495:129315)
at Ur (853a6cc8fc98e3350d02c9f99195b422.js:2495:46356)\