Welcome to Massager app support.
It looks like your Android don’t vibrate, and we’d be happy to look into this with you.
Go to Settings > Sound and vibration(Sound / Volume), check Vibration is turned on or off.
Reboot your phone, then check again.
If it happens only to this app, we recommend you remove it, then install it again.
Update your phone to the latest version.
Enter Settings > More settings > Backup & reset > Restore(Reset) all settings.
Do not worry, no data or media will be deleted.