To access and use an #Action Button , users need the following:

1. DSP Permission Set — At minimum, the DSP: Data Sync Pro Starter permission set.
2. Executable Record Access — At least Read access to the Executable record that defines the #Action Button. By default, every #Action Button is shared with all internal users through record sharing; this can be revoked by unchecking All Internal Users Have Read Access on the Executable.
3. Custom Permission (when applicable) — If the Access Permissions field is set on the Executable, users must have one of the specified custom permission(s) to see and use the action.
4. Scope Filter (when applicable) — When an #Action Button is placed on a Lightning Record, the current record must match the configured Scope Filter. If it doesn't, the #Action Button is hidden from the user.