PasteKeys needs permission to type into other apps. On macOS 27 and later, open System Settings → Privacy & Security → Device Control and Data Access and turn on PasteKeys. On earlier versions the same setting is called Accessibility. The Settings window in PasteKeys shows whether access is granted.
macOS describes this permission in broad terms. PasteKeys uses it only to type your clipboard, and has no network access.
macOS blocks all simulated typing while Secure Input is active. That happens in password fields, in Terminal with Secure Keyboard Entry turned on, and during Keychain prompts. Click into a normal text field and try again.
Paste as Virtual Keys sends US-keyboard key codes, so the receiving side needs a US layout. Characters outside plain ASCII, such as curly quotes, accents, and emoji, fall back to Unicode and may not survive a remote session. Retype those, or replace them before pasting.
If your Mac uses a non-US keyboard layout, use Paste as Unicode for local apps. It types the exact characters on any layout.
The target can't keep up. Open Tune & Paste, or Settings, and raise Delay between keys. Slow remote connections often need 30 ms or more.
Press Esc, or choose Stop Pasting from the menu bar icon.
Quit PasteKeys from its menu, then move it from Applications to the Trash.
Email support@pastekeys.app with your macOS version and what you were typing into.