All three work. You're ready.
Peeksolve remembered the check, so the reminder in its menu is gone. Now try it on real questions.
A key does nothing?
Click into this page first
The shortcut goes to the window in front. Click anywhere on this page, then press it again.
Another app or extension already uses the combination
Chrome only gives a combination to one extension. Pick a free one for Peeksolve on Chrome's shortcut page (copy the address into the address bar), or in Peeksolve's Settings → Shortcuts. Then reload this page.
chrome://extensions/shortcutsThe keys on the cards look different from mine
The cards show what Peeksolve actually has: ⌘ and ⇧ on a Mac, Ctrl and Shift on Windows and Linux. If you changed a shortcut, reload this page.
“Peeksolve isn't in this browser”
Add it from the Chrome Web Store, then reload. It works in Chrome, Edge, Brave and Arc.